Beam super surge methods and apparatus for small geostationary (geo) communication satellites

ABSTRACT

Disclosed embodiments relate satellites using a Software-Defined Radio (“SDR”) system. In one example, a geostationary (GEO) satellite includes an antenna system including multiple antennas, each configured to provide a spot beam having an adjustable throughput for a terrestrial coverage area while the antenna is in an active state and the satellite is in orbit above the Earth, a front-end subsystem communicatively coupled to the antenna system having an input side including an input filter and an analog-to-digital converter, and an output side including an output filter and a digital-to-analog converter, and a software defined radio (“SDR”) communicatively coupled to the antenna system via the front-end subsystem. The SDR, in response to a surge modification request, modifies a throughput of each active antenna by increasing or decreasing a share of a satellite power budget allotted to the antenna by deactivating or activating a previously active or previously inactive antenna, respectively.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/914,423, filed Jun. 28, 2020, which claims the benefit of priority ofU.S. Provisional Application No. 62/868,328 filed on Jun. 28, 2019,which are hereby incorporated by reference in their entirety and shouldbe considered a part of this specification.

BACKGROUND

Current commercial communication satellites are relatively large,expensive, and static in their operation. For example, many commercialsatellites designed to provide voice and data communications weigh inexcess of 15,000 pounds and cost over $300 million to develop, inaddition to the $100+ million to launch into orbit. For all the expenseand weight, known commercial satellites generally only provide fixedservices that are designed and provisioned years before the satellite iseven launched. For example, current commercial communication satellitesare custom-built, meaning they are designed with carrier frequencies,beamwidths, modulation protocols, and a network topology specified by anoperator. Oftentimes, it takes over five years to develop and launchcommercial satellites as a result of this customization.

To recoup the significant development costs, commercial satellites arerelatively large and designed to provide anywhere from 50 to 100 spotbeams. With such a large capacity, it may take an operator over a decadeto fully lease a commercial satellite. During this time, the unusedcapacity creates significant inefficiencies and increases the effectivecost per Mb transmitted. The large size and multiple licensees ofcommercial satellites also make them difficult or impossible toreposition or repoint. Further, it is generally not economicallypractical for an operator to launch a second satellite to cover gaps incoverage or augment coverage in growing markets. Moreover, it isgenerally not practical for an operator to have on-orbit redundantcommercial satellites given their significant expense. Large, expensive,inflexible commercial communication satellites are accordingly onlydeployed to cover areas that have large populations or entities willingto pay a significant amount for satellite coverage.

SUMMARY

The present disclosure describes a payload system that providescommunication flexibility or adjustability for small GEO communicationsatellites that use a Software-Defined Radio (“SDR”) system. The examplecommunication satellite (illustrated in FIGS. 1 to 7) is configured toprovide communication coverage between user terminals and one or moregateway stations. The flexibility of the payload system enables thecommunication satellite to change communication parameterspost-deployment to adapt to changing conditions, end-user needs, orsystem requirements. The flexibility also enables the communicationsatellite to provide communication coverage for specified areas fordefined periods of time, thereby providing an option for sharedsatellite coverage on-demand.

The example GEO communications satellite is configured to receiveover-the-air updates that can change operational parameters and providesystem flexibility. For instance, the GEO communications satellitedisclosed herein may be configured to provide a flexible carrierfrequency, flexible beamwidth, flexible channelization and routing,flexible beam shapes, beam hopping, and flexible network topology viaover-the-air updates. The example GEO communications satellite mayadjust signal amplitude and/or phase using low-element phased arraysand/or high-element phased arrays for forming beam shapes and beamhopping. In contrast, known commercial GEO satellites are static bydesign and do not permit or are incapable of adjustments in carrierfrequency, beamwidth, channelization/routing, beam shapes, beam hopping,and/or network topology.

In addition, the example GEO communications satellite disclosed hereinmay be configured to communicate with gateway stations at higherfrequencies compared to user links over, for example, millimeter-waveand/or optical links to provide more bandwidth for users. The GEOcommunications satellite disclosed herein may be configured with largeflexible aperture antennas, thereby improving data rates compared toknown satellite systems that generally have smaller (but more numerous)antennas. In some embodiments, the example GEO communications satellitemay have a single large flexible aperture and be provided in a networkwith other similar satellites with their own large flexible apertures.This provides a data rate advantage over known commercial satellitesthat are limited to a number of small apertures giving physical spacinglimitations.

The SDR system on the example GEO communications satellite enables noiseremoval, use of a compressed gateway spectrum, and equalization toimprove data throughput and overall system efficiency. Known commercialsystems typically do not have these features since they do not possessdigital signal processing capabilities. These improvements result inincreased system capacity and a lower cost of data transmission.

In some embodiments, the example GEO communications satellite isconfigured to operate with similar satellites to provide interlacedbeams. Further, the satellites may use intersatellite linking to formmesh networks. The intersatellite linking also enables certainsatellites to be provisioned as transmission-only or reception-only,and/or provide for gateway aggregation.

The example GEO communications satellite is configured to have a smallersize compared to commercial satellites. For example, the GEOcommunications satellite disclosed herein may have a size that is 1/10the size of a communication satellite. This small size enables the GEOcommunications satellite to be frequently repointed and/or relocatedover its life, with less fuel being required to perform the maneuvers.The smaller size and flexibility of the GEO communications satelliteenables it to be developed quickly (usually within 18 months fromcommissioning) and delivered to orbit within a shared rocket payload. Bycomparison, known commercial satellites may require five years fordevelopment to accommodate all the customization required for adedicated rocket launch, which can take time scheduling. In anotherapplication, the example GEO communications satellite disclosed hereincan provide a small capacity for a low cost that permits many uses thatare not practical for commercial satellite systems.

Chart 800 of FIG. 8 shows how the above-discussed features of theexample GEO communications satellite can be employed over one or moreuses, which are described further in connection with FIGS. 55 to 65. Anyone feature may enable any one of the corresponding uses. Additionally,it should be appreciated that any version of the example GEOcommunications satellite disclosed herein may be deployed with anynumber of features based on mission specifications.

The example GEO communications satellite disclosed herein has a lowercost per Mb/s compared to traditional satellites (see FIG. 61), whichenables it to be used in more economically sensitive locations and/ormissions. In addition, the example GEO communications satellite enablesan operator to test new markets (See FIG. 55) by deploying a smallsatellite to test a hypothesis or business case without having to investhundreds of millions of dollars in a large commercial satellite. Theabove features also enable operators to be responsive to changing groundor aero conditions (see FIG. 57) by providing rapidly deployable systemsand provide for bring-into-use (BIU) applications (see FIG. 60) when newfrequency spectrums become available. The example GEO communicationssatellite may provide an economical means to provide relatively smallbut important amounts of coverage by filling gaps in existing coverage(see FIG. 56), bridging traditional GEO capacity (see FIG. 58),phasing-in capacity over time based on demand (see FIG. 62), and/oraugmenting existing coverage (see FIG. 63).

The example GEO communications satellite also may be provided as aredundant system or spare (see FIG. 59). This redundancy enables theexample GEO communications satellite to provide an almost real-timeresponse to fill in for satellites that go offline or experiencefailures. Moreover, the example GEO communications satellite may beconfigured to repoint or reposition itself to provide time-varyingcoverage (see FIG. 64). For example, the example GEO communicationssatellite may repoint to follow primetime bandwidth usage throughdifferent time zones, provide seasonal coverage based on demand fromusers or customers, or provide capacity in response to terrestrialoutages during and after natural disasters. Additionally, the exampleGEO communications satellite may be dedicated entirely to a single endcustomer (See FIG. 65). The small cost of the GEO communicationssatellite makes it economically feasible for a single customer to have asatellite that is provisioned exactly for their requirements and pointedexactly where coverage is needed.

The following disclosure begins with a description of the examp554551ecommunications satellite, including a description of the SDR, antennas,and passive components. The disclosure then discusses satellite featuresthat are made possible by the disclosed satellite system. The disclosureconcludes by discussing novel uses of the example GEO communicationssatellite that are enabled by one or more combinations of the disclosedsystem features.

The example payload system disclosed herein includes an SDR that iscommunicatively coupled to one or more antennas via a front-endsubsystem. The SDR includes a processor, which may comprise any FPGA,GPU, CPU, ASIC, etc. The example payload system described hereinincludes an antenna system, front-end passive components, an adjustabletransmitter and receiver, a master reference oscillator, and the SDR. Insome embodiments, the payload system may include one or more filters,low-noise amplifiers (“LNAs”), down-converters, and analog-to-digitalconverters (“ADCs”) on a receiver side, and one or more filters, RFpower amplifiers (e.g., traveling-wave tube amplifiers (“TWTAs”)),up-converters, and digital-to-analog converters (“DACs”) on thetransmitter side. At least some of the amplifiers, filters, and/orconverters of the front-end system are adjustable components that permitparameter changes after deployment. In addition, the SDR includesadjustable parameters that provide further post-deployment flexibilityto the communication system. Moreover, the front-end subsystem may bemodular, enabling certain customization/provisioning per customerrequirements with minimal tuning of the SDR for compatibility.Altogether, the example SDR and front-end subsystem are configured toenable a flexible carrier frequency, flexible bandwidth, flexiblechannelization and routing, adjustable RF transmitted and receivedpolarization, compatibility with millimeter-wave and optical gatewaytransceivers, flexible beam shapes, beam hopping, interlaced beams, useof large flexible aperture antennas, use of low-element/high-elementphased arrays, noise removal and equalization, flexibility for acompressed gateway spectrum, flexibility for different networktopologies, capability for frequent body repointing and/or orbitalrelocation, and/or intersatellite linking for mesh networking, Rx and Txdedicated systems, and gateway aggregation, any of which may be updatedor provisioned post-deployment in over-the-air updates. Theabove-features of the example communication satellite system enables newmarkets to be tested, gaps in existing satellite coverage to be filled,rapid response to new and changing markets, bridging traditionalGEO-satellite capacity, on-orbit redundancy and response to failures,phased-in capacity, augmentation of existing capacity, time-varyingcoverage service, dedication to a particular customer, fast developmentand deployment for bring-into-use (“BIU”) circumstances, and lower costsper Mbps.

In an example embodiment, a payload system for a communicationssatellite includes an SDR configured to provide communication services.The SDR includes a processor configured to provide at least one of gaincontrol, channelization, beamforming, and channel routing for at leastone user slice or beam for a plurality of user terminals and at leastone gateway slice or beam for a gateway station. The example payloadsystem includes a front-end subsystem including an input side and anoutput side for each slice. Each input side includes an input filter, adown-converter, and an analog-to-digital converter, and each output sideincludes an output filter, an up-converter, and a digital-to-analogconverter. The payload system further includes a plurality of antennascommunicatively coupled to the front-end system.

The example down-converter and the up-converter of each slice areadjustable to enable a receive frequency and transmit frequency to betunable. In addition, the processor is configured to provide anadjustable bandwidth for each of the slices. The processor may also beconfigured to separate signals received from at least some of the slicesinto a plurality of narrowband channels, change a frequency and beamassignment for at least some of the channels based on a desired networktopology for at least one of the slices, and combine the narrowbandchannels for the at least one slice. The processor may further providefor flexible beam shapes by routing a single received signal out to adesired number of the output slices, where the processor adjusts a phaseand/or amplitude of a signal provided to each of the desired outputslices to change a shape of a coverage area. Additionally oralternatively, the processor is configured to provide for flexible beamhopping by routing a single received signal out to a desired number ofthe output slices, where the processor adjusts a phase of a signalprovided to each of the desired output slices to move a peak of acoverage area. Moreover, the processor is configured to provide fornoise removal by demodulating and decoding a received signal into adigital stream before encoding and modulating for transmission. Also,the processor may be configured to provide for signal equalization byequalizing a transmission signal before noise is added and/or configuredto provide for gateway spectrum compression by demodulating and decodinga received signal into a binary stream before encoding and modulatingfor transmission.

The advantages discussed herein may be found in one, or some, andperhaps not all of the embodiments disclosed herein. Additional featuresand advantages are described herein and will be apparent from thefollowing Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a diagram of an example communications satellite, accordingto an embodiment of the present disclosure.

FIG. 2 shows an example diagram of an SDR of the example communicationssatellite of FIG. 1, according to an example embodiment of the presentdisclosure.

FIG. 3 shows an example front-end system of the communications satelliteof FIG. 1 connected to the SDR of FIG. 2, according to an exampleembodiment of the present disclosure.

FIG. 4 shows a diagram of an example payload communications system ofthe communication satellite of FIG. 1, according to an exampleembodiment of the present disclosure.

FIGS. 5 to 7 show diagrams of different embodiments of the examplepayload communications system of FIG. 4, according to exampleembodiments of the present disclosure.

FIG. 8 shows a diagram of an example chart that shows a relation betweenfeatures of the example communications satellite, including the SDR ofFIG. 2 and corresponding uses cases supported by the features, accordingto example embodiments of the present disclosure.

FIGS. 9 and 10 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding carrierfrequency adjustability, according to example embodiments of the presentdisclosure.

FIGS. 11 to 14B show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding bandwidthadjustability, according to example embodiments of the presentdisclosure.

FIGS. 15 and 16 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regardingchannelization and routing flexibility, according to an exampleembodiment of the present disclosure.

FIGS. 17 and 18 show diagrams related to the communications satellite,including the SDR of FIG. 2 being configured to operate withmillimeter-wave and optical gateway transceivers, according to exampleembodiments of the present disclosure.

FIGS. 19 to 21 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding beam shapeflexibility, according to example embodiments of the present disclosure.

FIGS. 22 and 23B show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding beamhopping capability, according to example embodiments of the presentdisclosure.

FIGS. 24 and 25B show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding the use oflarge flexible aperture antennas, according to an example embodiment ofthe present disclosure.

FIGS. 26 and 27 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding the use ofinterlaced beams, according to an example embodiment of the presentdisclosure.

FIGS. 28 to 30 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding the use oflow-element and high-element phased arrays, according to an exampleembodiment of the present disclosure.

FIGS. 31 to 33 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding noiseremoval capability, according to example embodiments of the presentdisclosure.

FIGS. 34 and 35 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding compressedgateway spectrum, according to example embodiments of the presentdisclosure.

FIGS. 36 and 37 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regardingequalization capability, according to example embodiments of the presentdisclosure.

FIGS. 38 to 41 show diagrams that compare known satellite systems andthe example GEO communications satellite of FIG. 1 regarding networktopology flexibility, according to example embodiments of the presentdisclosure.

FIG. 42 shows a diagram of an example operating environment in whichcommunication satellites having the SDR of FIG. 2 operate together andare co-located within a single GEO orbital slot.

FIGS. 43 and 44 show diagrams related to mesh networking of the examplepayload communications system of FIG. 4, according to exampleembodiments of the present disclosure.

FIGS. 45 to 48 show diagrams related to specially configured satellites,according to example embodiments of the present disclosure.

FIGS. 49 and 50 show diagrams related to frequent body repointingfeatures of the communications satellite, according to an exampleembodiment of the present disclosure.

FIGS. 51 and 52 show diagrams related to frequent orbital relocationfeatures of the communications satellite, according to an exampleembodiment of the present disclosure.

FIGS. 53 and 54 show diagrams related to how a smaller capacity of theexample GEO communications satellite of FIG. 1 enables lower cost forthe same coverage area on the ground or air, according to an exampleembodiment of the present disclosure.

FIGS. 55 to 65 show diagrams related to unique uses of the example GEOcommunications satellite of FIG. 1 that cannot be economically performedby conventional satellites, according to example embodiments of thepresent disclosure.

FIGS. 66A to 77 show diagrams related to a beam super surgeconfiguration, according to example embodiments of the presentdisclosure.

DETAILED DESCRIPTION

The present disclosure relates in general to a flexible payload systemfor small communication satellites. The example payload system includesan SDR and a front-end system. The SDR includes a processor, such as afield-programmable gate array (“FPGA”) that implements traditionalcommunication hardware components, such as mixers, filters, amplifiers,modulators/demodulators, detectors, etc. as software. The SDR may alsoinclude analog components for signal filtering, amplification,up-conversion, and/or down-conversion. The example SDR may be configuredto provide for modulation and demodulation of any waveform, decoding andencoding of any waveform, channelization and routing, equalization,distortion compensation for channel effects, and RF Front Endimpairments. It should be appreciated that the processor of the SDR isnot limited to an FPGA and may include any ASIC, GPU, CPU,microcontroller, microprocessor, etc.

Reference is made herein to specific hardware configurations of anexample communications satellite. Reference is also made herein tocapabilities of an SDR. It should be appreciated that the example GEOcommunications satellite is not limited to the hardware configurationsdisclosed herein and may include alternative configurations and/orcomponents configured to perform the same operation or provide the sameresult. Further, some of the hardware configurations may instead beimplemented internally by a processor of the SDR, though, for example,through digital processing. It should also be appreciated that in someembodiments, operations performed by the processor may instead oradditionally be performed by hardware. The disclosure provided hereinprovides example embodiments regarding compositions of the examplecommunications satellite.

Reference is made throughout to features and uses of the examplecommunications satellite. It should be appreciated that a GEOcommunications satellite may be configured to perform all, or a subsetof the described uses based, for example, on provisioning. Further, itshould be appreciated that the GEO communications satellite may includeall or a subset of the described features, which enable the differentdescribed uses to be performed.

GEO communications Satellite Embodiment

FIG. 1 shows a diagram of an example GEO communications satellite 100,according to an example embodiment. The example satellite 100 isconfigured to provide communication services to aero or ground locationsusing a payload communications system 120. The satellite 100 transmitsand receives wireless signals using one or more antennas 103. Thesatellite 100 may include a first reflector 102 and a second reflector104 to direct the signals to the one or more feed antennas 103.

Together with the payload communications system 120, the example GEOcommunications satellite 100 is configured to provide SDR services tospecified aero or ground locations. The SDR services enablecommunication parameters to be changed as desired while the satellite100 is in orbit, including providing a flexible carrier frequency,flexible bandwidth, flexible channelization and routing, compatibilitywith millimeter-wave and optical gateway transceivers, flexible beamshapes, beam hopping, interlaced beams, use of large flexible apertureantennas, use of low-element/high-element phased arrays, noise removaland equalization, flexibility for a compressed gateway spectrum,flexibility for different network topologies, capability for frequentbody repointing and/or orbital relocation, and/or intersatellite linkingfor mesh networking, Rx and Tx dedicated systems, and gatewayaggregation, any of which may be updated or provisioned post-deploymentin over-the-air updates.

The example satellite 100 includes a structure 108 configured to encloseand/or provide structural support to the feed antennas 103, reflectors102 and 104, the payload communications system 120, battery, and othersubsystems disclosed herein. The satellite 100 is powered by at leastone on-board battery, which is recharged via solar arrays 110 and 112.The satellite may include an electric propulsion subsystem and/or amonopropellant subsystem for deployment, repositioning, orre-orientation.

The illustrated satellite 100 is relatively small compared to knowncommercial communication satellites. In an embodiment, the satellite 100has a height, length, and depth of 1 meter (“m”), thus having a volumeof 1 m³. In other embedment, the satellite 100 may be larger or smaller.For example, the satellite may have a volume as small as 0.65 m³ or avolume as large as 10 m³.

Payload System Embodiment

FIG. 4 shows a diagram of the example payload communications system 120of FIG. 1, according to an example embodiment of the present disclosure.The example system 120 is communicatively coupled to the feed antennas103 via one or more transmitting (e.g., TX) and receiving (e.g., RX)lines and signal multiplexers. In the illustrated embodiment, thepayload communications system 120 includes eight transmission lines(e.g., 8 intermediate frequency output ports with a 1.0 to 6.0 GHzcapability) and 8 receiving lines (e.g., 8 intermediate frequency inputports with a 0.5 to 5.5 GHz capability), thus creating 8 paths. In otherembodiments, the payload communications system 120 may include fewer oradditional lines.

The example SDR 206 of FIG. 2 is included within the system 120 andincludes an intermediate frequency (“IF”) board 202 configured toconvert signals for transmission or reception over the transmitting andreceiving lines. The payload communications system 120 also includes adigital board configured to process received signals for transmission.In the illustrated example, the IF board 202 includes amplifiers,filters, and up/down converters while the digital board 204 includesDAC/ADCs and an FPGA processor 302. In other examples, the IF board 202and the digital board 204 may be combined or components from the boards202 and 204 may be arranged differently. For example, in someembodiments, the DAC/ADCs may instead be located on the IF board 202.Alternatively, in some examples, the IF board 202 functionality may beincluded in upconverters 406 and downconverters 408.

The example SDR 206 is configured to process signals received on inputports or receiving lines for transmission via the output ports ortransmission lines. FIG. 2 shows an example diagram of the SDR 206,according to an example embodiment of the present disclosure. The SDR206 includes, in order from reception to transmission, interfacesconfigured to connect to the ADCs, gain control, IQ/DC compensation,channelization, equalization, beamforming processing, and channelrouting. In addition, for transmission, the SDR 206 includes beamformingprocessing, equalization, channelization, IQ/DC compensation, gaincontrol, and interfaces configured to connect to the DACs.

The channel routing may provide routing at one or many different networklevels. For example, the channel routing may route signals at a physicallevel, where signals having a certain specified carrier frequency arerouted to another channel. The channel routing may also provide routingat the network or hardware level, where data packets may be routed toother channels based on destination IP address, MAC address, etc.

FIG. 2 shows that the SDR 206 is configured for three user slices(labeled in the Figure as red, green, and blue) and one gateway slice.Each user slice communicates with a distinct gateway slice while thegateway slice combines/splits inputs/outputs to/from the three differentuser slices. Each slice includes a transmitting/output port and areceiving/input port, as shown in FIGS. 5 to 7. For reception, in theillustrated embodiment, the RF/IF front end includes a transmissionrejection filter (e.g., an LNA filter with isolator), and adown-converter. For transmission, in the illustrated embodiment, eachslice includes an up-converter, TWTA, and a reception band noiserejection filter. In other examples, the SDR 206 is configured tosupport additional or fewer slices. For example, the SDR 206 shown inFIG. 6 supports 5 different slices.

In the illustrated example, each input/output port corresponds to achannel, which may be divided into sub-channels (e.g., 2 MHzsub-channels). In addition, the SDR 206 of FIG. 2 may be configured toprovide equalization for the analog-RF front end and automatic gaincontrol with, for example, 40 to 45 dB of dynamic range). Further, theSDR 206 of FIG. 2 may be configured to provide 5 GHz of frequencyflexibility with 1 GHz, or more, of instantaneous bandwidth per port.

The SDR 206 (shown in FIG. 4) also includes a payload power board 208and an SDR power board 210. The payload power board 208 is configured toisolate a battery power supply from the payload communications system120 and establish a single point of ground for the SDR 206. The payloadpower board 208 may convert a 28-volt power supply to 5.5 v for the SDR206 and other components on the boards 202 and 204. The example SDRpower board 210 may include a buck converter configured to provide anadjustable voltage of 0.9 volts to 3.3 volts for the SDR 206 and/orother components on the boards 202 and 204.

FIG. 3 shows a diagram of a processor 302 (e.g., an FPGA) of the SDR 206that is communicatively coupled to one or more DACs 402 and one or moreADCs 404 for each input and output port. On the input side, the ADC 404,for each input or receiving line, is connected to a down-converter 406.On the output side, the DAC 202, for each output or transmission line,is connected to an up-converter 408. In the illustrated embodiment, theADC 404 and down-converter 406 provide for two separate slices. Inaddition, DAC 402, and the up-converter 408 provide for two separateslices. In other embodiments, only one channel may be provided, or morethan two slices may be supported (e.g., four slices).

In the illustrated example, the processor 302 is communicatively coupledto eight ADCs 404 and eight DACs 402. The eight input and outputconnections provided by the ADCs 404 and the DACs 402 may correspond to,for example, the 8 user/gateway inputs/outputs shown in FIG. 2 of theSDR 206.

The example ADCs 404 may have a sampling rate between 1000 MS/s and 20GS/s. In addition, the ADCs 404 may have an input bandwidth between 500MHz and 10 GHz, for example, around 5 GHz with 0.5 dB of ripple or 9 GHzwith 3 dB of ripple. Further, the ADCs 404 may have a resolution between9 bits and 20 bits, for example, between 10 and 14 bit with a resolutionwith +/−0.5b INL/DNL.

The example DACs 402 may have a sampling rate between 0.5 GS/s and 20.0GS/s. The example DACs 402 may also be configured to have sufficientlyhigh SFDR as to meet ITU emissions requirements. For example, the DACs402 may provide 60 dB SFDR at −2.4 dBm output power and have aresolution between 9 bits and 20 bits, for example, around 16 bits witha power ratio of −74 dBc SFDR at −7 dBFS output. Further, the DACs 402may be configured to provide internal interpolation of at least one of1×, 2×, 4×, or 8×.

The example down-converter 406 is configured to convert a receivedsignal to a lower frequency for digitization by the ADC 404. Theillustrated down-converter 406 of FIG. 3 includes a variable gain IFamplifier 410 configured to reduce the dynamic range of a receivedsignal (e.g., gain control). The downconverter 406 may be configured toprovide for IQ demodulation to retain phase information after atranslation to a baseband signal. The downconverter 406 includes afractional PLL configured to tune to a center frequency of a desiredchannel and lowpass filters to remove adjacent channels. The PLL of thedownconverter 406 may be configured to provide IF frequencies from 0.5to 6.5 GHz with phase noise under −110 dBc/Hz at 100 Hz and an outputpower of 3 dBm.

The example up-converter 408 is configured to process I and Q signalsfrom the DAC 402, which can be a dual channel DAC or of any otherarchitecture. The up-converter 408 includes low pass filters to removeDAC images and an IQ modulator to inject phase information into the IFcarrier signal. Fractional PLLs of the up-converter 408 are configuredto tune to a center frequency of a desired channel. The up-converter 408further includes a variable attenuator 412 (capable of providing up to12 dB of programmable attenuation) for high backoff when increasedlinearity is desired. In some embodiments, the attenuator 412 includesthe TWTA of FIGS. 5 to 7. The PLL of the up-converter 408 may beconfigured to provide IF frequencies from 0.5 to 6.5 GHz with phasenoise under −110 dBc/Hz at 100 Hz and an output power of 3 dBm. Theup-converter 408 may provide 500 MHz single-sided bandwidth and have a0.1 dB gain imbalance and 1.5 degree of phase imbalance.

The down-converter 406 and/or the up-converter 408 enable the SDR 206 toimprove rejection of adjacent channels, compensate for IQ imbalance,compensate for mixer local oscillator (“LO”) feedthrough, split a signalinto many 2 MHz subcarriers, and equalize linear distortion in the IFboard 202 (e.g., the front-end) and uplink channel. The PLL of thedownconverter 406 can be configured to provide IF frequencies from 0.5to 6.5 GHz with phase noise under −110 dBc/Hz at 100 Hz and an outputpower of 3 dBm. The downconverter 406 may provide at least 500 MHzsingle-sided bandwidth with about 42 dB of programmable gain with a 0.1dB gain imbalance and 1.5 degree of phase imbalance.

FIGS. 5 to 7 show diagrams of different embodiments of example payloadcommunications systems 500, 600, and 700, according to exampleembodiments of the present disclosure. The example SDR 206 is configuredto enable any of the embodiments of FIGS. 5 to 7 to be used based oncustomer or end-user specifications without significant modification ortuning. In other words, the embodiments of example payloadcommunications systems 500, 600, and 700 are modular and may replaceeach other for the payload communications system 120 described in FIGS.1 to 4. As described below, each of the embodiments provide differentcapabilities.

FIG. 5 shows red, green, blue, and grey slices (as labeled)corresponding to the inputs/outputs of the SDR 206 shown in FIG. 2. Thegateway slice is combined/split with the inputs/outputs of the threedifferent user SDR slices (green, blue, and red) via a duplex antennaconfiguration. In other embodiments, at least one slice may be dedicatedfor signals to/from the gateway via a dedicated duplex antenna. In theillustrated example, each user slice includes an input line/port andoutput line/port, which are connected at a duplexer or orthomodetransducer (“OMT”). The choice may depend on the antenna configurationimplemented. The input line 502 includes an input filter, such as atransmission band rejection filter and an LNA. The filter may beconfigured to pass frequencies between 27 GHz and 30 GHz or any otherrange depending on the operating frequency bands of the mission. Theinput line 502 further includes the downconverter 408. The output line504 includes a reception band noise rejection filter, a TWTA, and theup-converter 406.

In the illustrated example of FIG. 5, shaded components are active andmay be adjustable, which provides the front-end subsystem 500flexibility disclosed herein. Specifically, the TWTA, LNA, amplifiers,multipliers, PLLs and/or LPFs of the up-converter 406 and thedownconverter 408 are active components. The example configurationillustrated in FIG. 5 may be configured to provide one or more fixedbeams, including, for example, regional beams or High-throughputsatellite (“HTS”) spot beams. The adjustability of the front-end 500 (inaddition to the SDR 206) enables flexibility of the features discussedbelow.

The example front-end subsystem 600 of FIG. 6 includes similar inputlines 502, output lines 504, down-converters 408, and up-converters 406as the front-end subsystem 500 of FIG. 5. However, in the example ofFIG. 6, the system is configured to provide six user slices and onegateway slice. In this example, the six user slices are configured toprovide beams for user terminals while the gateway slice is configuredto communication with a gateway station. Similar to the front-end system500 of FIG. 5, the front-end subsystem 600 of FIG. 6 may be configuredto provide one or more fixed beams, including, for example, regionalbeams or HTS spot beams. The adjustability of the front-end 600 (inaddition to the SDR 206) enables flexibility of the features discussedbelow.

The example front-end subsystem 700 of FIG. 7 includes a switch betweentwo filters for each input and output line 502 and 504. On thetransmission side, a first filter may pass frequencies between 10.5 and11.5 GHz while the second filter passes signals between 11.0 and 13 GHz.In other examples, the switch may be removed and the input and outputlines 502 and 504 may each include a single filter.

The example front-end subsystem of FIG. 7 includes a beamformingcalibration network 702. The network 702 is configured to transmit andmeasure signals including, for example, different direct sequence spreadspectrum pseudonoise (“PN”) sequence on each transmit chain. The network702 may be configured to receive a different sequence on each receivechain for beamforming calibration. The beamforming calibration mayenable flexible beam shaping and/or beam hopping in addition toproviding one or more fixed beams, including, for example, regionalbeams or HTS spot beams. The adjustability of the front-end 700 (inaddition to the SDR 206) also enables flexibility of the featuresdiscussed below.

In either of the embodiments of FIGS. 5 to 7, the example SDR 206 may beconfigured with a regenerative configuration for increased computecapabilities. The increased capabilities include, for example, noiseremoval and a compressed gateway spectrum, as described below in moredetail.

Features of the Example Communications Satellite

As described above in connection with FIGS. 1 to 7, the example GEOcommunications satellite 100, including the SDR 206, provides forfeature flexibility and adaptability that enables a multitude ofdifferent uses. FIG. 8 shows a diagram of an example chart 800 thatillustrates a relation between features of the example GEOcommunications satellite 100, including the SDR 206 and correspondinguses supported by the features. The example features provided by the GEOcommunications satellite 100, including the SDR 206 comprise frequencyflexibility and efficiency, antenna flexibility, signal qualityenhancements, and flexibility based on a network or architecture.Frequency flexibility and efficiency includes flexible carrierfrequencies, flexible bandwidth, flexible channelization and routing,and/or the use of millimeter-wave and optical gateway transceivers.Antenna flexibility includes flexible beam shapes, beam hopping,interlaced beams, and/or the use of large flexible aperture antennas,low-element phased arrays, and high-element phased arrays. Signalquality enhancements include noise removal, compressed gateway spectrum,and/or equalization. Flexibility based on a network or architectureincludes a flexible network topology, frequent body repointing, frequentorbital relocation, inter-satellite linking, mesh networking acrosssatellites, Rx- and Tx-only satellite systems, fast build and deliveryto orbit capabilities, gateway aggregation, and/or small capacity forlow cost capabilities.

The example chart 800 of FIG. 8 shows how each of the mentioned featuresrelate to different uses, including testing for a new market, filing ingaps in existing coverage, rapid response to new and changing markets,bridging traditional GEO capacity, on-orbit redundancy and response tofailures, bring into use (“BIU”), lower cost per Mbps, phased-incapacity, augmenting existing capacity, serving time-varying coverage,and having dedicated satellite to end customer(s). For example, flexiblecarrier frequencies, flexible bandwidth, flexible channelization androuting, flexible beam shapes, flexible network topology, frequent bodyrepositioning, frequent orbital relocation, fast build and delivery toorbit, and small capacity for low cost features are conducive fortesting a new market for satellite coverage. It should be appreciatedthat while the example chart 800 provides an illustration of a relationbetween features and use cases, in some embodiments, fewer or additionalfeatures may be related to a particular use case and/or the GEOcommunications satellite 100, including the SDR 206 may be provisionedto support fewer features and only a subset of the use cases based onmission requirements.

The following sections describe features of the GEO communicationssatellite 100, including the SDR 206. A description of the use cases isprovided following the discussion of the features.

Flexible Carrier Frequency Embodiment

FIGS. 9 and 10 show diagrams related to the carrier frequencyflexibility of the payload communications system 120, including the SDR206. FIG. 9 shows a diagram of known satellite systems that typicallyinclude about 50 to 100 slices in which analog filters set the receiveand transmit frequencies. By comparison, FIG. 10 shows a diagram of theexample payload communications system 120 in which the receive andtransmit carrier frequencies are independently tunable. Theconfiguration shown in FIG. 10 includes fewer slices, such as eightslices. The example SDR 206, including the processor 302, may beconfigured to tune the frequency, based, for example, on instructionsreceived from a ground station. In other examples, the SDR 206 may tunethe transmit and/or receive frequencies in support of any of the usesdiscussed below in connection with FIGS. 55 to 65.

The frequency flexibility enables the example payload communicationssystem 120 to tune to a desired transmit or receive carrier frequency.The flexibility enables the payload communications system 120 to bedeployed for multiple service providers, for certain defined periods oftime. For example, the payload communications system 120 may be deployedfor a first provider to cover a communication outage or increase inbandwidth usage, then later switch frequencies for a second serviceprovider after service is no longer needed for the first provider. Inother words, the example payload communications system 120 provides asatellite-sharing capability. The flexibility also enables interferenceto be reduced by side-stepping the interfering frequencies.

In the illustrated example of FIG. 10, the payload communications system120 includes dual tunable oscillators as part of respective converters406 and 408. In other examples, the payload communications system 120may include a single tunable oscillator or instead adjust a carrierfrequency by adjusting gains of the ADC 404 and/or the DAC 402. In otherembodiments, the payload communications system 120 may use four or more,such as six, local oscillators with flexible up-conversion ordown-conversion architecture and frequency planning. In anotherembodiment, the payload communications system 120 may includeoscillators configured in multiple stages where frequencies are added,mixed, multiplied, and/or divided to achieve a desired carrierfrequency. It should be appreciated that any analog or digitalconfiguration may be implemented to provide for carrier frequencyadjustment.

In some instances, the configuration is different between the receiveand transmit sides. For example, a receive side may include a singletunable oscillator while the transmit side includes two oscillators thatprovide a mixed output. In addition, in some embodiments, theoscillators, in conjunction with the SDR 206, may be configured toprovide a set of discrete carrier frequencies. In other embodiments, theoscillators, in conjunction with the SDR 206, may be configured toprovide a continuous range of carrier frequencies.

Flexible Bandwidth Embodiment

FIGS. 11 to 14B show diagrams related to the bandwidth flexibility ofthe payload communications system 120. FIG. 11 shows a known satellitesystem in which fixed analog filters permit only one beam to passthrough. The filter has a fixed beamwidth of 500 MHz, for instance. Thisfixed configuration may be acceptable in some circumstances. FIG. 13shows a circumstance where three beams are received. The fixed bandwidthof the known system causes half of beams 0 and 2 to pass through the 500MHz filter.

In contrast to known satellite systems, the example payloadcommunications system 120 of FIG. 12 includes a digital filter providedby the SDR 206. In FIG. 12, the SDR 206 is configured to have abandwidth of 500 MHz to enable the only beam to pass through, similar tothe known system of FIG. 11. However, if the desired bandwidth per beamdecreases as multiple beams are received, the example SDR 206 isconfigured to accordingly adjust the bandwidth of the digital filter.For example, in FIG. 14A, the SDR 206 is re-configured to permit onlythe single beam by reducing the bandwidth of the digital filter to 250MHz.

The example SDR 206 is configured to enable the bandwidth to be adjustedbetween 1 MHz to 1 GHz (or more) via an over-the-update. In someembodiments, the SDR 206 may adjust filters to change the passband. Theuse of digital filters enables smaller guard bands to be used as aresult of sharper channel filtering, which may consume less than 1% ofthe available frequency spectrum compared to known systems that haveguard bands that consume upwards of 10% of the spectrum.

FIG. 14B shows a diagram comparing channel filtering of traditionalanalog systems 1402 and digital channel filtering 1404 provided by theSDR 206. Traditional analog filtering has a greater roll off at theedges compared to digital filtering. As a result, systems that usetraditional analog filtering have lower spectral efficiency factor, suchas 0.9, and need to allocate larger guard bands, such as 25 MHz. Bycomparison, the sharper digital filtering has a higher spectralefficiency factor, as high as 99%, and enables smaller guard bands to beused. The digital filtering accordingly provides a greater spectralefficiency factor and provides more available bandwidth for users.

The flexible bandwidth of the payload communications system 120 enablesa service provider to support increases in demand when additionalspectrum is not available. For example, a single payload communicationssystem 120 may be reaching capacity with 4 beams of 500 MHz bandwidth. Asecond payload communications system 120 may be provided operating onthe same spectrum, with each being configured to provide 4 beams of 250MHz bandwidth, which increases total capacity by 40%. The adjustabilityof the digital filter enables the bandwidth to be reduced so that onlythe desired beams are processed.

In another example, the payload communications system 120 is operatingat a frequency of 2 GHz, with 4 beams of 500 Mhz. A service provider maybe granted an additional 2 GHz of spectrum. Instead of launching anothersatellite, the service provider adjusts the bandwidth of the digitalfilters to operate over 4.0 GHz, where the bandwidth of the filters areincreased to 1 GHz (4 beams of 1 GHz), thereby automatically increasingcapacity by 60% without launching an additional satellite.

Flexible Channelization and Routing Embodiment

FIGS. 15 and 16 show diagrams related to channelization and routingflexibility of the payload communications system 120, according to anexample embodiment of the present disclosure. FIG. 15 shows a knownsatellite system in which analog transponders provide a rigid networktopology as a result of fixed, analog waveguide filters. The illustrateddesign is fixed during manufacture and provides for a pure hub-spokedesign where all signals received on a channel are routed to the sameoutput channel.

In contrast, FIG. 16 shows a diagram that is illustrative ofchannelization and routing configured within the SDR 206. The exampleSDR 206 includes a digital channelizer configured to enable flexiblenetwork topologies by using flexible digital filtering to separate areceived signal into many narrow band channels. For each channel, theSDR 206 may change a frequency and select a certain beam fortransmission. The selection may be in response to an over-the-airupdate. For transmission, the SDR 206 may combine many narrow channelsassigned to the same beam into a single signal, as shown in FIG. 16.

The example SDR 206 may provide routing at one or many different layers.For example, the SDR 206 may be configured to provide physical layerrouting such that sub-channels of a specified frequency are routed toanother channel. This may be performed for spectrum allocation or loadbalancing. The SDR 206 may also perform routing at the link or networklayer by routing digital data based on MAC or IP address. In theseexamples, the SDR 206 may include a routing-and-forwarding table thatspecifies to which sub-channel data is to be routed.

Millimeter-Wave and Optical Gateway Embodiment

FIGS. 17 and 18 show diagrams related to the GEO communicationssatellite 100 configured to compatibility with millimeter-wave and/oroptical gateway transceivers, according to an example embodiment of thepresent disclosure. FIG. 17 shows a diagram of a traditional satellitethat communicates with gateway transceivers 800 operating in the samefrequency as the use spectrum (i.e., the Ka band) or in another commonuser link frequency. For instance, the gateway may operate in the Kaband while the user links are provided in the Ku band. In thisconfiguration, significant high-value spectrum is consumed by thegateway link with the satellite. In some instances, the limited spectrumavailable for the gateway 800 is the bottleneck for network capacity.

FIG. 18 shows an embodiment of the GEO communications satellite 100,including the SDR 206 configured to communicate with a gateway 1800 thatis configured to communicate over a higher frequency compared to theuser links. The higher frequency may comprise the Q-band, the V-band,the W-band, or an optical band, which are generally less suitable foruser links and where spectrum is generally more plentiful. Communicationover these bands between the gateway 1800 and the satellite 100 providesmore bandwidth for the low-frequency, high-value user links in the Ka orKu band. The use of higher frequencies for the gateway link also enableshigher directivity on the gateway link, thereby reducing the transmitpower requirements and enabling greater spectral efficiency factorvalues. This configuration may also reduce the number of gateways neededsince frequency reuse is not as critical. As discussed above, theexample SDR 206 is configured to provide the frequency flexibilityand/or demodulation/modulation needed to enable millimeter-wave and/oroptical communication with gateways. In some instances, the SDR 206 mayadditionally or alternatively be configured to facilitate user links inthe higher frequency bands.

It should be appreciated that the example SDR 206 may also be configuredto process different waveforms. Different service providers may havedifferent waveforms, some being proprietary. The SDR 206 may beconfigured to process a first waveform on a gateway link whileprocessing second different waveforms on a user link. Further, the SDR206 may receive over-the-air programming to change the waveform beingprocessed by, for example, adjusting digital filter parameters,adjusting DAC/ADC gain values, and/or adjusting carrierfrequency/bandwidth.

Flexible Beam Shape Embodiment

FIGS. 19 to 21 show diagrams related to the beam shape flexibility ofthe payload communications system 120. FIG. 19 shows a diagram of acoverage area of known satellites. Generally, the beam shapes (driven bythe radiation pattern of the antenna) are fixed.

FIGS. 20A and 20B shows diagrams of example beams or radiation patternsprovided by the example payload communications system 120. In thisexample, the four narrow beams from FIG. 19 are re-configured by the SDR206 into a single wide beam. The beam may be provisioned for broadcasttelevision, for example. The single elongated beam shown in FIG. 20A hasconsistent Quality of Service (“QoS”) coverage throughout the servicearea.

The elongated beam shown in FIG. 20A is one example of a formed beamshape. It should be appreciated that a combined and/or individual shapeof beams may take many forms depending on the terrestrial coverageneeded. For example, one or more beams may be formed into a triangularcoverage area, an L-shaped coverage area, etc. FIG. 20B shows an exampleof a possible beam shape. The example SDR 206 may achieve the beam shapeshown in FIG. 20B via an over-the-air update which adjusts an amplitudeand/or phase of signals entering/leaving each feed on an antenna feedplane. The amplitude and/or phase may be adjusted via a gain varyingamplifier, controllable phase shifters, and/or turning on/off certainantennas in an array. The example SDR 206 may provide for separate beamforming for each sub-carrier channel to produce virtually any radiationpattern. As such, the beam forming described herein may be performeddigitally within the SDR 206, via analog components, and/or acombination of both.

FIG. 21 shows a diagram of the SDR 206 configured for providing flexiblebeam shapes using a phased array, which is described below in additionaldetail. In the illustrated example, the SDR 206 is configured to route areceived signal to four transmitters. (In other embodiments, the signalmay be routed to fewer or additional transmitters). The SDR 206 adjustsamplitude and phase of the signal for each transmitter to fine tune theshape of the desired beam. In some embodiments, the SDR 206 receivesinstructions, including phase and/or amplitude information from a groundstation. In other examples, the SDR 206 is configured to select thephases and/or amplitudes based on a received indication of a coveragearea, QoS requirements, etc. The example beamforming calibration network702 of FIG. 7 may be used to maintain the relative phases and/oramplitudes as the signal propagates through the transmitters.

Beam Hopping Embodiment

FIGS. 22 to 23B show diagrams related to the beam hopping capability ofthe payload communications system 120. FIG. 22 shows a diagram of aknown satellite system providing a fixed wide-area beam. The knownsatellites systems are constrained to providing low signal levelsthroughout the coverage area due to the large geographic area covered.This configuration can be problematic for high throughput cases.

In addition to providing a flexible beam shape, the example SDR 206 ofthe payload communications system 120 is configured to enable one ormany small beams to be moved within a coverage area, as shown in FIG.23A. This configuration enables a relatively large amount of bandwidthto be provisioned for a small geographic location. In an example, one ormore cruise ships may be within a coverage area. Each cruise ship hasthousands of passengers that provide a significant bandwidth load in arelatively small area. Instead of a bandwidth-constrained wide beam, theexample SDR 206 may create a small beam with high signal levels focusedon the cruise ship. In addition, the SDR 206 may cause the beam tofollow a path of the cruise ship or jump between cruise ships. As aresult, the SDR 206 is able to provide a 5 dB stronger signal whileimproving average system capacity by 50−100%, for example. The examplepayload communications system 120 may provide beam hopping for otherembodiments, such as satellite service-sharing for providingcommunication coverage for a large festival or conference taking placefor a limited duration in a remote location.

The example SDR 206 may be configured to provide beam hopping based onan over-the-air instruction and/or according to a predetermined routine.The SDR 206 may adjust the location of the beam as quickly as every 5 msto maximize the gain experienced by a user, thereby increasing capacityon both the forward and return links. The SDR 206 may adjust a locationof beam by adjusting an amplitude and/or phase of signals entering andleaving each feed on the feed plane, using for example a phased array orany of the operations discussed above in connection with FIGS. 20A, 20B,and 21.

FIG. 21 shows a diagram of the SDR 206 configured for providing beamhopping. In the illustrated example, the SDR 206 is configured to routea received single to four transmitters. (In other embodiments, thesignal may be routed to fewer or additional transmitters). The SDR 206adjusts a phase of the signal for each transmitter/receiver to move thepeak of the transmitted/received beam. In addition, the SDR 206 adjustsphase and amplitude of the signal for each transmitter/receiver to finetune the shape of the desired beam. The SDR 206 may also adjust theamplitude of the signals.

In some embodiments, the SDR 206 receives instructions, including phaseand amplitude information and a location for the beam (e.g., a positionof a cruise ship) from a ground station. In other examples, the SDR 206is configured to select the phase and amplitude based on a receivedindication of a coverage area, geographic location, QoS requirements,etc. In other examples, the SDR 206 may track a moving object, therebydetermining a location for a beam. The SDR 206 may track by moving thebeam in different directions and determining to which direction has thegreatest bandwidth consumption, which is a modified version of theconical scanning method used in radars making it suitable for satelliteapplication. The example beamforming calibration network 702 of FIG. 7may be used to maintain the relative phases and amplitude as the signalpropagates through the transmitters and/or receivers.

FIG. 23B shows a diagram that illustrates how an array of antennasfeeding a reflector can be selectively turned on to move a beam quickly.Graph 2450 shows a relation between reflector antenna beamwidth (e.g.,coverage area on the Earth) in degrees and a feed horn aperture size.The graph 2450 shows that as the aperture size increases from 2 to 12.3mm, the beamwidth increases from 1.6 to 5 degrees. In a staticembodiment, different feed horns with different aperture sizes may beused. The SDR 206 may select which feed horn is to be used based on thecoverage area requirement. By contrast, in a dynamic environment, theSDR 206 may be connected to an array of smaller feed horns withidentical apertures. The SDR 206 is configured to control excitations ofthe individual feed horns in the array to create different effectiveaperture sizes. For instance, in the illustrated embodiment, activatingonly one element (A) will provide a smallest effective feed size whileturning on all the elements (D) will provide the largest feed size. TheSDR 206 may achieve anything in between by exciting a subset of theelements in a discrete manner, as shown in (B) or by exciting allelements and controlling the excitations with more granularity forcontinuous control, as shown in (C).

Large Flexible Aperture Antenna Embodiment

FIGS. 24 to 25B show diagrams related to capabilities of the GEOcommunications satellite 100, including the SDR 206, regarding the useof large flexible aperture antennas, according to an example embodimentof the present disclosure. As shown in FIG. 24, known satellites areconstructed as single-piece structures such that antenna sizes arelimited in diameter. The size limitation on the antenna limits maximumequivalent isotropically radiated power (“EIRP”) and gain tonoise-temperature (“G/T”), which limits data throughput. Many knownsatellites, as shown in FIG. 24, use multiple small to medium (e.g., 1to 2 meter) reflectors.

FIG. 25A shows an example of the GEO communications satellite 100 withantennas with larger apertures. While the use of large apertures is notnew, the use of large flexible aperture antennas on a relatively smallGEO communications satellite is unique. The antennas may be stowed forlaunch and deployed and expanded when the GEO communications satellite100 is in orbit (hence called “flexible”). The GEO communicationssatellite 100 may include an unfurlable mesh antenna, an expandableantenna, a deployable or foldable (flexible or solid) antenna, aflexible (compliant solid) antenna, and/or a stowable array antenna(forming various types of flexible antennas). The GEO communicationssatellite 100 may be configured specifically to provide a largeraperture antenna and provide for a unique deployable structure withoutconstraints from other adjacent antennas or space limitations within thehousing. As shown in FIG. 25A, the use of the larger reflector, alongwith proper feed architecture, enables more spot beams to be provisionedfor the same data rate as shown in FIG. 24 at a substantially lowercost.

FIG. 25B shows an example regarding how the GEO communications satellite100 may be launched with a large flexible aperture antenna. In theillustrated embodiment, an antenna is packed into a very small volumeduring launch (and orbit raise depending on mission requirements). Thepacking enables an antenna with more than a 5× aperture size to be used,which would occupy the same volume as a traditional reflector antenna.After the satellite 100 is positioned, the antenna with the largeflexible aperture is unfurled, thereby providing a dramatic savings intime and cost of the mission while providing unprecedented data rates.

Interlaced Beams Embodiment

FIGS. 26 and 27 show diagrams related to capabilities of the GEOcommunications satellite 100, including the SDR 206, regarding the useof interlaced beams, according to an example embodiment of the presentdisclosure. FIG. 26 shows a figure of a known satellite with multipleapertures. In the illustration, the multiple apertures (shown asAperture 1 and 2) and reflectors provide different interleaved beams.The illustrated configuration requires a large satellite with multipleapertures and reflectors to achieve a tight-arrangement or packing ofbeams.

By comparison, FIG. 27 shows a diagram of multiple communicationsatellites 100 (shown as satellites 100A and 100B) that are arranged toachieve a tight packing of separate beams. In the illustrated example,each of the communications satellites 100 may include only a singleaperture such that the beams from each satellite 100 are interleaved.This arrangement of single-aperture satellites 100 enables capacity tobe phased-in or a sub-set of capacity to be repointed or any otheruse/advantage of providing a small, single-aperture satellite. Theillustrated satellites 100A and 100B are specifically orientated andcoordinated with respect to each other to provide for the tight-packingof beams without having to compensate for aperture or reflector size ororientation, thereby enabling single aperture satellites to achieve theperformance of known conventional, multiple aperture satellites.

Low-Element and High-Element Phased Arrays Embodiments

FIGS. 28 to 30 show diagrams related to capabilities of the GEOcommunications satellite 100, including the SDR 206, regarding the useof low-element phased arrays, according to an example embodiment of thepresent disclosure. FIG. 28 shows a diagram of a known satellite where asingle feed per beam is configured. The single feed per beam generallyresults in an inflexible beam footprint on the ground. In addition,power needed to supply the single feed is relatively high to drivecostly, but highly efficient, conventional traveling wave tubeamplifiers.

FIG. 29 in contrast shows the satellite 100 with the SDR 206 having arelatively low number of feed elements. Generally, phrased arrays arecomplex to implement based on the large number of elements needed.However, the example SDR 206 reduces element complexity via dynamicdigital control of the amplitude and phase for the elements in thearray. The SDR 206 provides software control of amplitude and/or phaseof each transmission/reception signal for each feed. As discussed above,this amplitude and/or phase flexibility enables dynamic beam shapes andbeam-hopping. In some instances, a relatively low element count phasedarray may not generate the directivity needed for a link. As a result,the GEO communications satellite 100 may include one or more reflectorsurfaces to improve link directivity.

FIG. 30 shows the satellite 100 with the SDR 206 having a multiple feedfor a relatively large number of elements. The satellite 100 may includea large number of low-power solid state power amplifiers (SSPAs), highelement count, and/or software control of signal amplitude and/or phasevia the SDR 206. The illustrated configuration enables a highlydirective, highly steerable beam footprints. In addition, theillustrated phased array is configured to directly radiate towards theEarth, thereby removing the need for any reflectors.

Noise Removal Embodiment

FIGS. 31 to 33 show diagrams related to the noise removal capability ofthe payload communications system 120. FIG. 31 shows a known satellitein which noise is propagated from uplink (receive) to downlink(transmit). This causes the known satellite to transmit degraded signalquality, and waste power on noise transmission, which could lead tolosses in signal strength by up to 6.5 dB.

FIG. 32 shows a diagram of the example payload communications system 120removing virtually all interference and noise from a signal beforeretransmitting to a gateway or user terminal. In the illustratedexample, the signal to noise ratio is maintained at 10 dB. This can beespecially important when the payload communications system 120, via theSDR 206 is configured to route traffic between adjoining beams, whichmay create signal interference. By removing the noise and interferencebetween the adjacent beams, the SDR 206 is capable of improving signalquality by more than 3 dB at the user terminal, thereby increasingcapacity by over 30% between the adjoining beams.

FIG. 33 shows a diagram of the example SDR 206 regarding its noiseremoval capabilities. To remove noise, the example SDR 206 is configuredto demodulate and decode a received signal into a digital or binarystream of ‘1s’ and ‘0s’. This may be provided in conjunction with signalrouting between slices, as described above in regard to networktopology. For transmission, the digital signal is reconstructed viamodulation and encoding and transmitted on the desired slice.

The example SDR 206 is configured to remove noise in any waveform via anover-the-air update specifying, for example, the waveform parameters formodulation in addition to processing and filtering. In some examples,the SDR 206 may operate in connection with hardware componentsconfigured to remove noise from a signal. Additionally, oralternatively, the SDR 206 may provide noise removal via regenerativedigital signal processing.

Compressed Gateway Spectrum Embodiment

FIGS. 34 and 35 show diagrams related to the compressed gateway spectrumcapability of the payload communications system 120. FIG. 34 shows adiagram of a known satellite system in which a modulation and encodingscheme is provisioned in which an eight symbol constellation is used onthe user links and the same eight symbol constellation is used on thegateway links, where the modulation is the same for the user and gatewaylinks. In some known systems, the satellite system may be provisionedsuch that a different modulation and encoding scheme is used for thegateway link because the gateway terminal is larger. This enables themodulation used for the gateway to be more spectrally efficient.However, the known satellite systems are fixed in that the modulationand coding cannot be changed after deployment. Thus, if conditionschange or service is provided for a different provider, the provisionedmodulation and encoding scheme may not be sufficient. For example, asmaller gateway could be installed or used. However, the known satellitehas already been provisioned to operate efficiently with a largergateway.

In some instances, the gateway and user links may use the samemodulation and coding for known satellite systems. The gateway link mayuse the same modulation and coding despite the gateway link havingsignificantly more C/N margin. The reason for this is because conventiontransponders on known satellites are incapable of altering themodulation and coding of a received signal before retransmitting.

The example payload communications system 120 of the GEO communicationssatellite of FIG. 35 is configured to change modulation and encodingschemes for any of the user or gateway slices. For example, upon use ofa larger gateway, the SDR 206 may change a modulation and coding schemeto one that is more spectrally efficient, thereby allowing spectrum tobe repurposed and used to increase system capacity or throughput by atleast 15% without increasing the spectrum allocated to the gateway. Thisadditional spectrum can be used for serving additional content, forexample. In other words, spectrum saved on the gateway link can beprovided by the SDR 206 for user links. In the illustrated example, theSDR 206 may provide eight symbols on user links or slices and 64 symbolson the gateway links. Accordingly, the SDR 206 enables the modulationand coding for the gateway link to be independent of the modulation andcoding used for the user links, which are often C/N limited.

FIG. 33 shows a diagram of the example SDR 206 regarding compressedgateway spectrum capabilities. The example SDR 206 has software-baseddemodulators/decoders and modulators/encoders. The SDR 206 may selectbetween the different programmed demodulators/decoders andmodulators/encoders for each slice or link. This may be provided inconjunction with signal routing between slices, as described below inregard to network topology. For transmission, the digital signal isreconstructed via the selected modulation and encoding and transmittedon the desired slice or link.

Equalization Embodiment

FIGS. 36 and 37 show diagrams related to the equalization capability ofthe payload communications system 120. Generally, known satellitesystems are not capable of providing equalization. Instead, userterminals provide equalization of the received satellite signal.However, equalization performance by ground receivers is limited sincesignificant thermal noise has been introduced before the equalization isperformed. FIG. 36 shows that for known systems, user terminals equalizethe received signal but amplify the noise significantly in the process.The amplification of noise, especially at higher frequencies, can lowerthroughput by at least 10%, especially when operating in ultra-widebandchannels, such as 500 MHz and above.

In contrast to known satellite systems, the example SDR 206 of thepayload communications system 120 (included in the satellite 100) isconfigured to equalize the signal before downlink noise is added,thereby leaving a relatively small amount of equalization to be done bythe user terminal. As shown in FIG. 37, the example SDR 206 isconfigured to provide digital equalization, which corrects for (i)different frequencies having slightly different gains/losses passingthrough the atmosphere (e.g., rain, clouds, scintillation in thetroposphere), filters, amplifiers, etc., and (ii) different frequenciestaking different amounts of time to propagate through the atmosphere,filters, amplifiers, etc. that may affect or introduce signal gainslope, reflections, and/or group delay distortion. The equalizationperformed by the SDR 206 means there is less amplification of noise bythe user terminal, and thus a higher capacity link, thereby improvingthe data rate of the system.

The example processor 302 may include a 12-bit complex tap applied toeach 2 MHz subcarrier, as described above in connection with the networktopology flexibility. The processor 302 in other embodiments may includean 8-bit complex tap up to a 24-bit complex tap. In some instances, thetaps may be determined via calibration over temperature and frequency,or in a closed loop adaptive fashion.

Flexible Network Topology Embodiment

FIGS. 38 to 41 show diagrams that compare known satellite systems andthe example GEO communications satellite 100 regarding network topologyflexibility. FIG. 38 shows a diagram of coverage areas for knownsatellite systems. The systems are configured in a hub-and-spokeconfiguration where at least one beam 3800 is dedicated for a gatewaystation while separate beams are provided for user terminals. In thishub-and-spoke configuration, the satellite system causes allcommunications to be routed through the gateway station, whichdetermines whether the communications are to be routed to another userterminal in the same or a different beam.

In contrast to the known satellite systems, the example payloadcommunications system 120 is configured to be able to support virtuallyany network topology, including mixing network topologies. FIG. 39 showsan example of network topologies supportable at the same time by theexample payload communications system 120. Similar to the known systems,the payload communications system 120 supports a hub-and-spoke topology.Additionally, the example SDR 206 of the payload communications system120 enables other network topologies to be supported, such asuser-to-user (shown as links 3902), mesh, and/or a combination ofhub-spoke and user-to-user. In some embodiments, the network topologymay vary over many time scales (e.g., seasonally, daily, hourly, etc.).The SDR 206 is configured to adjust to the network topology viaover-the-air software or digital logic updates, which provides flexiblechannelization and routing for steering traffic.

The SDR 206 may be provisioned via over-the-air programming to support aspecified topology. In a combined topology, the SDR 206 may route databased on network or link layer protocols to enable data to betransmitted in a return link or routed to another satellite. In anexample, the SDR 206 (and/or a ground station) may detect that a gatewaylink or beam is close to capacity. However, a significant amount oftraffic originates and ends in one beam. Instead of sending thisidentified traffic to the gateway station, the example SDR 206 isconfigured to route the traffic back through the beam to the destinationterminals, thereby reducing the traffic on the gateway beam. Thus, theSDR 206 saves gateway spectrum and power and improves networking speedsby eliminating one receive/transmit route on the gateway link. The SDR206 may read a destination address (and/or use geolocation data relatedto the destination terminal) to identify to which beam a communicationis to be routed.

In another example, the SDR 206 (and/or a ground station) may detectthat a large data center is located in a user beam or link. Instead ofsending all of the traffic through the gateway link, the SDR 206 isconfigured to determine user beams for the traffic. Accordingly, the SDR206 routes network traffic directly to a destination user terminal,thereby saving bandwidth usage on the gateway link and improving networklatency.

FIG. 40 shows a diagram of the example SDR 206 configured to supportmultiple network topologies. Sub-channels can be flexibly linked acrossslices by the SDR 206, enabling network traffic to be routed internallywithin the example payload communications system 120, rather thansending all received communications to a ground-based gateway station.In the illustrated example, more of the bandwidth is reserved forrouting to/from a gateway station. However, at least some bandwidth isallocated between the different user slices (e.g., links or beams). Forexample, 100 MHz of bandwidth is provisioned between a blue user sliceand a red user slice. It should be appreciated that in some embodiments,each user slice may have at least some bandwidth allocated for routingtraffic to each of the other user slices (as well as the gateway slice).

FIG. 41 shows a diagram of features of the SDR 206 for providing aflexible network topology, in some embodiments. The example SDR 206 isconfigured to separate the received signals into many narrowbandchannels. For example, a 1.0 GHz signal may be separated into 500 2.0MHz subcarriers. In other examples, a 1.0 GHz signal may be separatedinto 2, 500 MHz subcarriers or 250, 4 MHz subcarriers. Thisconfiguration removes adjacent channels to the 1.0 GHz signal (to −40dBc). The SDR 206 may achieve channel separation via a polyphase filterbank, or any digital filtering structure. The polyphase filter may have,for example, an input sample rate of 1250 MHz for 14 bit I and Q, a passband of 1.0 MHz with 2.0 MHz two-sided passband, a stop band start of3.0 MHz, a transition band of 2.0 MHz, a pass band ripple of 0.1 dB, anda stop band rejection of 92.0 dB to ensure aliasing into the passband isat most −40 dBc in the presence of adjacent interference at +26 dB SD.

For signal routing, the example SDR 206 is configured to change thefrequency and/or beam assignment of each narrowband channel. The SDR 206then combines the many narrowband channels for each transmit beam beforetransmitting. The SDR 206 may achieve signal construction via apolyphase filter bank, or any digital filtering structure.

Intersatellite Linking and Mesh Networking Embodiments

In some embodiments, the example GEO communications satellite 100 mayoperate in coordination with other similar communication satellites 100.FIG. 42 shows a diagram of an example operating environment 4200 inwhich communication satellites 100 operate together and are co-locatedwithin a single GEO orbital slot. In the illustrated example, thecommunications satellites 100 a, 100 b, and 100 c are providingcommunication coverage to an area 4202 on the Earth 4204. In addition,the GEO communications satellite 100 d is provisioned as a spare. Whilethe illustrated example shows four satellites, it should be appreciatedthat other operating environments may include fewer or additionalsatellites. For example, the environment 4200 may include 10 to 40 (forexample, around 15) relatively small satellites providing communicationcoverage to a continuous area or separate areas that are relativelyclose in proximity compared to a size of Earth's surface area (e.g.,covering the main islands of Indonesia). In addition, the operatingenvironment 4200 may include at least two spare satellites 100 d.

The communication satellites 100 are provisioned such that satellites100 a, 100 b, and 100 c are each assigned a coverage area. The spot beamplacement, satellite orientation, coverage areas, coverage shapes,bandwidth/channel allocation, frequency use/reuse, coding/encryptionprotocols, and/or network topology provided by the satellites 100 isconfigurable via respective SDRs 206. The communication satellites 100may be provisioned with the communication parameters prior to launchand/or post launch via a ground station 4206. The provisioning of thesatellites 100 causes them to operate together to provide continuous,substantially uniform communication coverage to an area on the ground.

In some embodiments, the satellites 100 are configured to communicatewith each other. In these embodiments, the satellites 100 each include awireless transceiver and antenna that is configured to transmit andreceive communication parameters and instructions outside of a frequencychannel/band used for providing services to the ground units. In someembodiments, the satellites 100 may be configured to communicate over amicrowave or optical band in a mesh network. The satellites 100 may alsohave steerable or directional antennas that are configured to point toan adjacent satellite, thereby creating a mesh network. In otherinstances, the satellites 100 may have unidirectional antennas due tothe close proximity of spacecraft.

In contrast to the embodiment shown in FIG. 42, known commerciallyproduced satellites communicate only with user terminals or gateways onthe ground. Generally, the satellites are not configured to communicatewith each other. Oftentimes, the satellites are not visible to eachother or are too far away to enable effective intersatellitecommunication. For example, FIG. 43 shows known satellite configurationswhere data can only pass between two satellites through the groundstations or gateways.

In some instances, the mesh configuration of the satellites 100 shown inFIGS. 42 and 44 may provide gateway sharing or direct user-to-userconnections. The mesh network enables more flexible network topologies,spectrum savings, power savings, and lower latency. The meshconfiguration provided at least by the satellites 100 a and 100 benables direct user-to-user connections, thereby saving transmissiontime and reducing lag. As discussed above, the SDR 206 is configured touse link-layer or network-layer routing to determine which data packetsare to be transmitted on a sub-carrier, or over a particularintersatellite link. In addition, the mesh configuration enables moreflexible network topologies, spectrum savings, power savings, etc.

In some examples, the SDRs 206 may be configured to determine whencapacity has been reached, or close to being reached. Accordingly, theSDRs 206 may send instructions to one or more adjacent satellites 100with information indicative of the spot beams in which capacity islimited, causing one or more other satellites (with available capacity)to change at least one of spot beam's shape/location, frequency,bandwidth, etc. to provide additional capacity. This enables additionalsatellites 100 to overlay more capacity for a certain geographic area ontop of existing beams.

In addition to providing coordination for capacity, the satellites maycommunicate among each other to cover when one satellite is takenoffline for software updates/refreshes, taken offline due to low batterypower, taken offline to correct an operational issue, or removed fromservice. The satellites 100 may also communicate among each other toadjust for local weather or other environment issues and/or adjust forchanges in population density. As such, the satellites 100 mayreconfigure themselves to account for satellites going offline. In theillustrated example, the satellites 100 may be programmed with acomplete coverage area in addition to the capabilities of the satellite100, in addition to a starting provision of services. The satellites 100may then coordinate in orbit among themselves to best maintain thedesired coverage area using the flexibility provided by the SDR 206.

In some instances, the satellites 100 may be in communication with theground station 4206, which may provide provisioning instructions. Thesatellites 100 may be in direct communication with a ground station viaa directional antenna or communication with the ground station 4206 viacommunication gateways that are located in coverage areas. In thisinstance, the satellites transmit their capacity, bandwidth, and otherparameters to the ground station 4206. The example ground station 4206uses one or more optimization algorithms to change the communicationparameters to address current conditions. In this example, the groundstation 4206 determines how each satellite 100 should be provisioned andtransmits one or more messages to the appropriate satellites 100 withthe new provisioning information.

In other instances, the satellites 100 and the ground station 4206 areconfigured to operate together to dynamically change communicationcoverage. For example, the satellites 100 may communicate among eachother to adjust for relatively minor issues (and transmitting this tothe ground station 4206) while the ground station 4206 provides commandsfor relatively larger changes in provisioning/adjusting communicationparameters and/or orbits. In some instances where the satellites havelimited or no inter-satellite communication capability, the groundstation 4206 and/or gateways may route provisioning or controlinstructions between the satellites 100.

In the illustrated example, the satellite 100 d is provisioned as aspare. Given the relatively small and inexpensive nature of thesatellites, an operator can deploy spares without absorbing asignificant cost or needing to seek an immediate return. The sparesatellite 100 d may be in the same orbital location as the othersatellites 100 a, 100 b, and 100 c. Alternatively, the spare satellite100 d may be assigned to a different orbit. The example spare satellite100 d may be quickly brought online in near real-time to provide, forexample extra capacity or provide as a backup in the event one of theother satellites goes offline. The space satellite 100 d may receiveprovisioning instructions (and/or orbital realignment instructions) fromat least one of a satellite 100 that has been (or will be) takenoffline, a satellite 100 operating at close to capacity, one of thesatellites 100 provisioned to provide coverage close to an area wherethe satellite 100 d is to operate, and/or the ground station 4206.

The configurability and coordination among the relatively smallsatellites 100 via the SDR 206 enables coverage areas to be tuned toground demographics and/or topography. This enables the satellites 100to be placed strategically. By comparison, relatively large satellitesare designed to provide communication coverage to wide areas and aregenerally static in their deployment for the reasons discussed above.The post-deployment configurability of the satellites 100 permitsoperators to construct coverage areas that match the ground. Forexample, coverage areas could be positioned along major transportationlines, population centers, and ground topology. This prevents, forexample, bandwidth from being wasted in open water, deserts, ormountainous areas. The coverage areas may take on any shape sincemultiple satellites 100 may coordinate together, each capable of formingtheir own beam shapes. Ground patterns may include s-shapes, narrowlines or bands, rings, triangles, rectangles, etc. (with no or reducedcoverage in the center), grids, etc.

Specially Provisioned Satellite Embodiments

FIGS. 45 and 46 show diagrams related to how the example communicationssatellites 100 may be specially provisioned for one particular task,according to an example embodiment of the present disclosure. FIG. 45shows a diagram of a known satellite system in which two parabolicdishes are used, where one dish is used for transmission and another isused for reception. In some instances, the reception dish is made lessparabolic to achieve the same directivity as the transmit dish despitethe higher frequency of the received signals. Overall, the known systemprovides a compromise between the reception and transmission side oroptimizes for transmission while making reception significantly lessefficient or robust.

In contrast, the example communication satellites 100 of FIG. 46 areconfigured to intersatellite communications, as discussed in connectionwith FIGS. 42 and 44. In this embodiment, the satellite 100 a isoptimized for uplinks while the satellite 100 b is optimized fordownlinks. In other words, the aperture of the satellite 100 a isoptimized for receiving signals while the aperture of the satellite 100b is optimized or specifically shaped for transmission. For transmissionto the ground, the satellite 100 a transmits signals to the satellite100 b via an intersatellite link, which then provides for downlinktransmission. The SDR 206 in each satellite enables the signals to berouted across channels as part of the transmission path.

Generally, since the satellites 100 are smaller, compared to a singlesatellite shown in FIG. 45, they may be developed faster with lessoverall cost. Further, it is easier to add smaller satellites to alaunch schedule since a single rocket does not need to be dedicated tolaunch only these specific satellites. For example, the satellites 100may find room in a rocket configured to launch many smaller satellites.

It should be appreciated that the satellites 100 may be specialized inother ways other than transmission and reception. For example, FIGS. 47and 48 show how the satellites may be configured based on link type.FIG. 47 shows a diagram of a known satellite system in which satelliteshave gateway transmitters and receivers capable of providing all userlinks. Accordingly, each satellite has to be in communication with atleast one gateway.

In contrast, FIG. 48 shows an embodiment where the satellites 100 a and100 b use an intersatellite link, as discussed above in connection withFIGS. 42 and 44 to enable the satellite 100 b to be specificallyconfigured for providing only user links. The SDR 206 b of the satelliteis configured to use physical, network, or link layer routing of gatewaytraffic to the satellite 100 a via the intersatellite link. The SDR 206a of the satellite 100 a is configured to add the data from thesatellite 100 b to the gateway link for transmission to the gateway. Assuch, both satellites 100 a and 100 b share the same gateway whileenabling the satellite to be specifically configured for providing userlinks. This configuration alleviates the need for additional gateways,which can save a customer millions of dollars. Further, the satellite100 b may be provisioned to provide service in situations which agateway is not present.

Frequent Body Repointing Embodiment

FIGS. 49 and 50 show diagrams related to frequent body repointingfeatures of the GEO communications satellite 100, according to anexample embodiment of the present disclosure. FIG. 49 shows a diagram ofa known satellite system in which the satellite contains a large numberof transponders that serve many markets. Given the spread of themarkets, the satellite is required to stay in the orientation, since asmall shift could cause a service disruption in one or more areas.Further, many known satellites are not capable of re-pointing since theyrely on horizon sensors to maintain a specified orientation.

In contrast, FIG. 50 shows a diagram of the example GEO communicationssatellite 100, which is configured to repoint. The satellite 100 has acapacity and coverage area that is generally below the capacity demandvariation of a given network. As such, the satellite 100 may beconfigured to re-point towards peak demand on a seasonally, weekly,daily, or hourly basis. For example, the satellite 100 may follow primetime demand across different time zones. The satellite 100 achievesfrequent re-pointing via flexible attitude determination, such asstar-gazer sensors and/or a sun sensor. This flexibility enables thesatellite to point anywhere on the visible earth during its lifetime. Inaddition, the small size of the satellite 100 enables sufficient powermargins to enable frequent re-pointing.

Frequent Orbital Relocation Embodiment

FIGS. 51 and 52 show diagrams related to frequent orbital relocationfeatures of the GEO communications satellite 100, according to anexample embodiment of the present disclosure. FIG. 51 shows a knownsatellite initially covering the continental United States from anorbital slot of 90W. The satellite is configured on the ground such thatthe antennas provide beams that coincide with the borders of the U.S.The antennas are fixed in place to provide a fixed beam pattern inaddition to a frequency plan. Thus, if the satellite is moved to slot10E, the beam pattern of the U.S. would provide insufficient coverage ofland and water over Europe and North Africa and the Middle East.

In contrast, FIG. 52 shows a diagram in which the example GEOcommunications satellite 100 is initially providing coverage over cruiselines in the Caribbean from orbital slot 90W. At a later time, thesatellite 100 is moved to slot 10E, where beam shapes and coverage areasmay be modified to cover cruise lines in the Mediterranean Sea. Thisconfiguration enables the satellite 100 to change orbital slots on afrequent basis, such as a seasonal or monthly basis. The flexiblefrequency, beam shape, and flexible channelization provided by the SDR206 in addition to hardware enables better re-use over differentgeographic areas. Further the smaller size of the satellite 100 reducesthe amount of fuel needed for relocation to enable many relocations overa lifetime.

Small Capacity and Fast Build Embodiment

FIGS. 53 and 54 show diagrams related to how a smaller capacity of theexample GEO communications satellite 100 enables lower cost for coveringthe same area on the ground or air, according to an example embodimentof the present disclosure. FIG. 53 shows a known satellite system thattypically costs $150 to $400 million to produce and launch. Thesatellite is configured to cover the entire continental United Stateswith over 50 static beams. As such, the known satellite has a custompayload which is purpose-built for a given service region. Thiscustomization requires long development time for design andmanufacturing, which can span over three years. Further, since thesatellite requires a dedicated launch, launch opportunities are morelimited.

In contrast, FIG. 54 shows the example GEO communications satellite 100,which costs a fraction of the larger satellite of FIG. 53. As shown inthe illustrated example, the satellite 100 provides fewer beams as aresult of its smaller size. However, additional similar satellites 100may be deployed to cover the entire continental United States, which isstill less expensive than the single satellite. Further, as describedabove, the satellites are flexible and can individually be adjustedafter launch based on ground conditions, customer requests, etc. whilethe known satellite of FIG. 53 is only provisioned for providingcoverage for the Eastern continental United States.

The GEO communications satellite 100 may be available off-the-shelf orbe developed and built in a shorter time, such as 18 months. The abovedescribed flexibility of the satellite 100 means that less customizationper customer is needed, thereby reducing development time. Many nearlyidentical satellites 100 may be built together to dramatically reducenon-recurring engineering effort and provide for a constant supply chainand holding stock. The satellites may be built during the same run on aproduction line, thereby having a shorter lead time, higher throughput,and lower overall cost. Further, the smaller size of the satellite 100provides more launch opportunities.

Use Embodiments

The example GEO communications satellite 100 described above may beprovisioned for various uses in which conventional, known satellitescannot economically be deployed. The features described above inrelation to the SDR 206 and the satellite 100 overall permit the noveluses. For example, the relatively small and inexpensive nature of theexample communication satellites 100 disclosed herein enable them to bedeployed to test or develop an initial market. The low cost of thesatellite reduces the cost risk for the operator, compared to the costof a larger satellite. The smaller satellite could be deployed to testhow much demand there is for satellite service in a certain area orprovide coverage as part of an incentive to market and develop satelliteservice in a particular area. As demand increases and the market isestablished, the satellite 100 could be replaced by a larger satellite,or additional satellites 100. The additional satellites may also enablethe coverage area to be expanded to larger geographic areas, therebyscaling communication coverage in proportion to demand.

FIGS. 55 to 65 below describe at least some of the unique uses of theexample satellite 100. It should be appreciated that any individualsatellite may be provisioned to perform all the described uses or only asubset of the uses. Further, while the features shown in chart 800enable the uses, it should be appreciated that not every feature isrequired for the use to be implemented. For example, for testing a newmarket, any of the flexible carrier frequency, flexible bandwidth,flexible channelization and routing, flexible beam shape, and flexiblenetwork topology may be enabled on the satellite 100 and implemented inthe SDR 206.

A. Testing a New Market

FIG. 55 shows a diagram related to a use of the GEO communicationssatellite 100 for testing a new market. New geographic and verticalmarkets may require connectivity that is best served by satellites.However, as new markets, the economic hypothesis needed to be testedwithout dedicating a significant investment. Known satellites are tooexpensive and inflexible to be deployed in a new market. Instead, theexample satellite 100 provides the low-cost and flexibility required totest new coverage areas. As shown in FIG. 55, the new markets mayinclude vehicles (e.g., ships, buses, cars, etc.) with satelliteconnectivity and geographic areas not currently served by satellites.Flexible carrier frequency, flexible bandwidth, flexible beam shapes,flexible network topology, frequent orbital relocation, fast build anddelivery to orbit, and small capacity for low cost individually or inany combination enable the satellite 100 to test for new markets.

B. Filling in Coverage Gaps

FIG. 56 shows a diagram related to a use of the GEO communicationssatellite 100 for filling in gaps in existing coverage. Locations 5602represent coverage areas provided by traditional, known satellites. Asan example, there is a gap in coverage along the North Atlantic route.This gap is not covered commercially given the relatively high cost ofdeploying an additional conventional satellite. In other instances,conventional satellites trade off coverage for performance and cost,thereby creating gaps in areas.

In the illustrated embodiment, the satellite 100 is deployed for fillingin the North Atlantic route, as shown by highlighted locations 5604. Thefast build and delivery to orbit in addition to the low cost enables thesatellite 100 to be deployed to provide economical coverage in a knowngap. In addition, the SDR 206 may provide flexible beam shapes to coveruniquely shaped gaps.

C. Rapid Response to New and Changing Markets

FIG. 57 shows a diagram related to using the GEO communicationssatellite 100 for providing rapid response to new and changing markets.It should be appreciated that conditions on the ground are constantlychanging. For example, urbanization, commercialization, immigration, newtechnologies, and other socioeconomic factors change market needs andcan accordingly shift coverage needs to new or different geographicareas. Traditional known satellites cover large areas ranging from tensto thousands of customers. The dynamics of these large areas can changeover time, thereby rendering satellite coverage unnecessary in somecovered areas. While this occurs, the satellite misses out onopportunities for coverage elsewhere and is inflexible to adapt to newmarkets. In addition, larger satellites are more difficult to steer orrelocate, making any coverage changes extremely difficult.

In contrast to known satellites, the example GEO communicationssatellite 100 can be quickly deployed based on demand. For example, FIG.57 shows the GEO communications satellite 100 providing coverage for theWestern United States and Texas in 2018. However, based on changes, in2020 the GEO communications satellite 100 is deployed to eastern partsof the United States. Flexible carrier frequency, flexible bandwidth,flexible beam shapes, beam hopping, flexible network topology frequentbody repointing, frequent orbital relocation, and fast build anddelivery to orbit individually or in any combination enable thesatellite 100 to provide a rapid response to new and changing markets.

D. Bridging Traditional GEO Capacity

FIG. 58 shows a diagram related to using the GEO communicationssatellite 100 for bridging traditional GEO capacity. In some instances,a plan may be in place to provide satellite coverage to a largegeographic area, as shown by the coverage area planned for satellite5800. However, as described above, traditional satellites usuallyrequire at least three years of lead time. In the meantime, a subset ofhigher-priority customers with the geographic area may require coveragesooner. Rather than go without coverage, the example satellite 100 maybe quickly deployed to provide coverage for critical areas 5802. Afterthe satellite 5800 comes online a few years later, the satellite 100 maybe redeployed for another use. Flexible carrier frequency, flexiblebandwidth, flexible beam shapes, beam hopping, flexible networktopology, frequent body repointing, frequent orbital relocation, fastbuild and delivery to orbit, and small capacity for low costindividually or in any combination enable the satellite 100 to bridgetraditional GEO capacity.

E. On-Orbit Redundancy and Response to Failures

FIG. 59 shows a diagram related to using the GEO communicationssatellite 100 for providing on-orbit redundancy and rapid response tofailures. In the illustrated example, satellites 100 are provisionedinitially as spare or redundant satellites. If a satellite experiences afailure, the redundant satellite can quickly come online and take theplace of the failed satellite. The lower cost of the satellites meansless capital is expended to provide satellites with redundancy orbackup. Flexible carrier frequency, flexible bandwidth, flexible beamshapes, beam hopping, flexible network topology, frequent bodyrepointing, frequent orbital relocation, fast build and delivery toorbit, and small capacity for low cost individually or in anycombination enable the satellite 100 to provide on-orbit redundancy andresponse.

In contrast, known commercial satellites are not deployed solely forredundancy based on their cost. Some known satellites may have redundanttransponders for backup. However, this is not sufficient backup forsystem-level failures or in the event the satellite goes completelyoffline.

F. Bring-Into-Use (“BIU”)

FIG. 60 shows a diagram related to using the GEO communicationssatellite 100 for providing BIU services. On occasion, the FCC or othergovernment bodies make spectrum (e.g., a specific set of frequencies)available to the public or for specified commercial purposes. Generally,satellite operators are given priority access if they can deploy asatellite for the newly available slot within three years. As discussedabove, traditional satellite programs can require at least 3 to 4 yearsto place a new satellite into orbit, which makes meeting a BIU deadlinedifficult. Further, customer requirements cannot be easily repurposedfor a BIU application, especially if the customer requirements are notyet known or developed.

In contrast, the example satellite 100 may quickly be brought into use.For example, a satellite may be developed and launched in as soon as 18months, meeting the BIU launch requirements. In other instances, acustomer may request access to a redundant or spare satellite 100already in orbit to provide almost instantaneous BIU. In yet otherinstances, the satellite may use beam hopping to test a new BIUspectrum/location before a license expires to determine if renewal isjustified. In addition, flexible carrier frequency, frequent bodyrepointing, frequent orbital relocation, fast build and delivery toorbit, and small capacity for low cost individually or in anycombination enable the satellite 100 to provide relatively fast BIUservices.

G. Lower Cost per Mb/s Coverage

FIG. 61 shows a size comparison between a conventional satellite and theexample GEO communications satellite 100 disclosed herein. Theconventional satellite costs between 300 to 500 million to develop andlaunch based on lead time. For example, a satellite that requires a leadtime of over five years can cost over $300 million to develop inaddition to $100+ million to launch, while a satellite that requiresbetween three to five years of lead time can cost between $150 to $400million to develop and launch. By comparison, the example GEOcommunications satellite 100 costs $10 to $20 million, approximately,and can be developed in as short as 18 months. The example GEOcommunications satellite 100 has lower power consumption from use offewer antennas, less system hardware, smaller system busses, and smalleroverall platform. The lower power consumption enables the example GEOcommunications satellite 100 to have smaller solar arrays. Further, thesmaller size makes it much easier to repoint and reposition the exampleGEO communications satellite 100.

The example SDR 206 provides flexibility, as described above, which whencombined with the small size and unique large antenna enables a highthroughput, which lowers the cost per MB/s. The lower cost makes it moreattractive to deploy the example GEO communications satellite 100 formost cost-sensitive markets. All of the features described aboveindividually or in any combination enable the satellite 100 to providelower cost per MB/s coverage, and in particular, the features offlexible carrier frequency, beam hopping, large flexible apertureantenna, noise removal, compressed gateway spectrum, equalization,flexible network topology, frequent body repointing, frequent orbitalrelocation, fast build and delivery to orbit, and small capacity for lowcost enable the satellite 100 to provide this use.

H. Phased-in Capacity

FIG. 62 shows a diagram related to using the GEO communicationssatellite 100 for phasing-in capacity. Graph 6202 shows how muchbandwidth is wasted when a traditional satellite is initially deployed.As described above, traditional satellites have significant amount ofcapacity. However, it may take up to a decade for all of the capacity tobe leased. The idle capacity over this decade leads to a high cost perunit.

In contrast, graph 6204 shows how the satellites 100 may beincrementally deployed to scale with capacity. This enables a satelliteoperator to efficiently increase capacity over time to match demandwithout having excess unused capacity. After ten years in theillustrated example, the five satellites serve the same market at thesame time and may be configured to provide interlaced beams. Flexiblecarrier frequency, flexible bandwidth, flexible beam shapes, beamhopping, interlaced beams, flexible network topology, fast build anddelivery to orbit, and small capacity for low cost individually or inany combination accordingly enable the satellites 100 to providephased-in capacity.

I. Augmenting Existing Capacity

FIG. 63 shows a diagram related to using the GEO communicationssatellite 100 for augmenting existing capacity. In many cases, a singleknown, conventional satellite is close but not sufficient to meet thedemands of a region. Deploying a second traditional satellite tocompletely meet the demands may not be cost efficient. Coverage areas ingrowth zones are especially prone to running out of satellite capacity.

In the illustrated example, the shaded regions show satellite groundcoverage. Region 6302 corresponds to a location where existing satellitecapacity has been exhausted. It is usually cost prohibitive to deploy a$300 million satellite to accommodate the growth. Instead, the exampleGEO communications satellite 100 may be configured to provide beams 6304to address the capacity issue, thereby providing capacity for growth. Inthis manner, the example GEO communications satellite 100 may augmentcapacity provided by traditional satellites. Flexible beam shapes, beamhopping, large flexible aperture antenna, noise removal, compressedgateway spectrum, equalization, flexible network topology, fast buildand delivery to orbit, and small capacity for low cost individually orin any combination accordingly enable the satellites 100 to provideaugmented capacity.

J. Serving Time-Varying Coverage

FIG. 64 shows a diagram related to using the GEO communicationssatellite 100 for serving time-varying coverage. Mobility markets, suchas aero and land mobile, as well as traditional markets can haveshifting coverage needs that vary over time, such as seasonally, weekly,daily, hourly, etc. Traditional satellites are inflexible and provideservice to a mix of mobility and non-mobility-based customers that havedifferent needs. As a result, the satellite is prevented from servingtime-varying needs in a cost-effective manner without sacrificingcoverage or high capacity utilization for at least some customers. Inother words, large satellites typically cannot move one beam withoutaffecting the other 50 to 100 beams.

In contrast the example GEO communications satellite 100 is configuredto provide real-time adjustments to coverage for meeting customerdemand. In the illustrated example, the satellite 100 initially providesbeams 6402 for providing capacity to cruise lines in the Caribbean fromOctober to May. Then, from June to September, the satellite 100 providesbeams 6404 for providing capacity to cruise lines in the Mediterranean.The satellite 100 accordingly provides coverage where cruise lines arelocated during peak seasons. Flexible carrier frequency, flexiblebandwidth, flexible beam shapes, beam hopping, flexible networktopology, frequent body repointing, frequent orbital relocation, andsmall capacity for low cost individually or in any combinationaccordingly enable the satellites 100 to provide time-varying coverage.

K. Dedicated Satellite to an End Customer

FIG. 65 shows a diagram related to using the GEO communicationssatellite 100 for providing dedicated services for a customer. Withconventional satellites, customers lease a portion of availablecapacity. Since the satellite has a uniform platform and networktopology, customers that lease the same satellite have to share theplatform and network among each other, thereby limiting their individualflexibility and leading to burdensome costs. For example, when acustomer wishes to change a market they serve, they cannot relocate thesatellite because it is shared with other customers. Instead, thecustomer needs to find a new satellite.

In contrast the example GEO communications satellite 100 of FIG. 65 maybe dedicated to a sole customer. In this embodiment, the customer may bea cruise ship operator. The configurability of the satellite 100 inconjunction to the customer being the only user gives the customer ahigher degree of freedom, adaptability, and control over coverage. Thelow cost of the satellite makes it economically viable for a customer toown or lease a complete satellite for themselves. In addition, Flexiblecarrier frequency, flexible bandwidth, flexible beam shapes, beamhopping, flexible network topology, frequent body repointing, frequentorbital relocation, and small capacity for low cost individually or inany combination accordingly provide unique features that make itattractive to dedicate the satellite 100 completely for an end customer.

Beam Super Surge Embodiments

In some embodiments, the example GEO communications satellite 100disclosed herein is configured to provide a select number of beams to beactivated in a certain area based on throughput and/or usage needs orrequirements.

In one example, a geostationary GEO satellite, such as GEO satellite 100shown in FIG. 1, includes an antenna system including multiple antennas,each configured to provide a spot beam having an adjustable bandwidthfor a terrestrial coverage area while the antenna is in an active stateand the satellite is in orbit above the Earth. The GEO satellite caninclude a software defined radio (“SDR”) communicatively coupled to theantenna system via a front-end subsystem. The front-end subsystem has aninput side including an input filter and an analog-to-digital converter,and an output side including an output filter and a digital-to-analogconverter.

The SDR, in response to a surge modification request, modifies abandwidth of each active antenna by increasing or decreasing a share ofa satellite power budget allotted to the antenna by deactivating oractivating a previously active or previously inactive antenna,respectively. The surge modification request can include a predeterminedroutine, instructions received from a ground station, or an indicationof a coverage area.

In one example, the SDR implements a super-surge by dynamicallyincreasing forward throughput to a target region requiring higherbandwidth. For example, in some embodiments, the SDR increases powerprovided to a first antenna illuminating the target region bydeactivating a second, previously active antenna immediately adjacent tothe first antenna. The first antenna thus becomes a sole recipient of apower amplifier that previously also provided an input to the secondantenna.

The ground station, sometimes referred to as an earth station, or earthterminal, is a terrestrial radio station designed for extraplanetarytelecommunication with spacecraft. Ground stations may be located eitheron the surface of the Earth, or in its atmosphere. In some embodiments,the ground station is a teleport that communicates with the satelliteaccording to International Telecommunication Union RadiocommunicationSector (ITU-R) standards. Some teleports are satellite ground stationsthat connect a satellite with a terrestrial telecommunications network,such as the Internet.

Teleports may provide various broadcasting services among othertelecommunications functions, such as uploading computer programs orissuing commands over an uplink to a satellite

FIG. 66A shows a diagram of three scenarios 6602, 6604, and 6606 inwhich certain beams may be activated to provide communication coveragefor three different flight paths over the continental United States.Scenario 6602 shows an instance where twenty-four beams are active toprovide generally uniform coverage to each cell and the flight paths.The circles without interior shading correspond to beams that are notactive. As shown in the chart below, the forward throughput per beam is520 Mbps. In contrast, scenario 6604 shows an instance where only 12beams are activated for three different flight paths. In this instance,the forward throughput is doubled to 1040 Mbps per beam. Further,scenario 6606 shows an instance where only 6 beams are activated toprovide converge for a few high-traffic airports. Here, the forwardthroughput is 2080 Mbps. This illustrates a super surge concept wherethe forward throughput increases as less beams are used.

As illustrated in FIG. 66A, the satellite may provide spot beam coveragewhere the bandwidth for different terrestrial coverage have differentforward throughput or have no throughput for inactivated beams. Thisallows the satellite to increase or decrease throughput for particulargeographic areas. Additionally, the satellite may be configured orinstructed to modify the throughput over a path of multiple areas. Forexample, the satellite may provide a higher throughput from an Easternto Western direction while tracking a moving ground station. Also, thesatellite may be configured to increase throughput for areas terrestrialareas, such as for cities, or other areas where high throughput isneeded. The satellite may reduce throughput for other areas, orcompletely inactivate a beam where terrestrial coverage is not needed.

FIG. 66B illustrates a method of provisioning spot beams for aterrestrial coverage area, according to some embodiments. As shown,method 6650 starts at 6655. At 6660, the method calls for providing aGEO communication satellite including an antenna system comprising aplurality of antennas, each configured to provide a spot beam having anadjustable bandwidth for a terrestrial coverage area while the antennais in an active state and the satellite is in orbit above the Earth. At6665, the method calls for providing a front-end subsystemcommunicatively coupled to the antenna system, the front-end subsystemcomprising an input side including an input filter and ananalog-to-digital converter, and an output side including an outputfilter and a digital-to-analog converter. At 6670, the method calls forproviding a software-defined radio (“SDR”) communicatively coupled tothe antenna system via the front-end subsystem. At 6675, the SDR is torespond to a surge modification request, by modifying a bandwidth ofeach active antenna by increasing or decreasing a share of a satellitepower budget allotted to the antenna by deactivating or activating apreviously active or previously inactive antenna, respectively. At 6680,the SDR is to check whether a new surge modification request has beenreceived. If not, at 6685, the SDR is to wait for a predetermined amountof time before checking again. The predetermined amount of time could bea few seconds, a few minutes, a few hours, a few days, and so on. But,if the SDR determines at 6680 that a new surge modification request wasreceived, the SDR returns to 6675 to respond to the new request.

The satellite power budget can vary according to the size of the GEOcommunications satellite 100, and will depend on the size and efficiencyof the solar panels 110 and 112, as well as the capacity of the on-boardbattery in the payload communications system 120, which is recharged bythe solar panels. To calculate the satellite budget, the power consumedby the major components of the satellite can be estimated and tabulated.Recommendations and method for calculating and optimizing satellitepower budgets are promulgated by the International TelecommunicationUnion Radiocommunication Sector (“ITU-R”) and are available as an ITU-Rpublication at http://www.itu.int/en/ITU-R/Pages/default. aspx.

To cite an example, the tiny, 1,000 cm{circumflex over ( )}3 CubeSatsatellite developed in part by the California Polytechnic StateUniversity and Stanford University, became a catalyst for NASA's CubeSatprogram. Typically, the 1U, 2U, and 3U CubeSats' maximum satellite powerbudgets range from 1 to 2.5 Watts, 2 to 5 Watts, and 7 to 20 Watts,respectively, as published athttp://www.ann.ece.ufl.edu/pubs_and_talks/Aero12_arnold_ERB.pdf.

To cite an example of a larger satellite, the Pratham spacecraft,operated by the Indian Institute of Technology Bombay, is a cube havingapproximately 12-inch sides and weighing around 22 pounds. The Prathamsatellite power budget is around 11 Watts. as published athttps://www.aero.iitb.ac.in/satelliteWiki/index.php/Main_Page.

FIG. 67 shows a relationship between the active beams shown in FIG. 66and which feed elements of an antenna array are activated thatcontribute to the formation of the beam. In the illustrated example, theGEO communications satellite 100 disclosed herein may be capable ofproviding 37 different beams, with, for example, as many as 24 beamsbeing active at the same time. It should be appreciated that fewer than24 beams may be active at the same time and still make use of asignificant portion of the satellite's capacity. In other embodiments,the GEO communications satellite 100 may have power capabilities toactivate all 37 beams at the same time.

To provide for the 37 different beams, 61 different feed elements areused. As shown seven feed elements (sometimes referred to herein as“feed horns”) are provided to contribute to the formation of each beam.Overlap between circles indicates that the same feed element included inboth circles contributes to the formation of both beams.

FIGS. 68 to 71 show diagrams illustrative of a reflector and feedelements of the example GEO communications satellite 100 disclosedherein. FIG. 68A shows different reflector designs, including a uniformdesign, a prime focus feed, a dual reflector without a hole, a dualreflector with a 300 mm hole, and a duel reflector with a 500 mm hole.The graphs in FIG. 68B show average and peak directivity in dB for eachof the different designs. The graphs also show sidelobe level (“SLL”) indB for Ku-band transmission at 11 GHz and reception at 13 GHz. On thesegraphs, side lobe level is defined as a side lobe level below a mainbeam, and thus a higher number means a lower sidelobe (e.g., dB downfrom a peak value). As shown, the uniform design has the bestdirectivity and expected peak sidelobes 17 dB below peak directivity. Incomparison, the prime focus feed and dual reflector without a hole haverelatively lower directivity but lower sidelobe levels. The dualreflector with the 500 mm hole has higher sidelobe levels and lowerdirectivity. The dual reflector with a 300 mm hole provides potentiallyadequate sidelobe levels while also providing relatively robustdirectivity compared to the prime focus feed and has the advantage ofreduced overall size due to the folded or compressed optics of the dualreflector system. As such, the example GEO communications satellite 100disclosed herein may include a dual reflector with a 300 mm hole toprovide for the beams shown on FIGS. 66 and 67.

FIGS. 69A to 71B show how a reflector feed size was selected for thedual reflector with the 300 mm hole. FIG. 69A shows a graph 6900 thatrelates peak directivity to feed horn diameter, where optimaldirectivity for the Ku-band case studied is around 80 mm for the conicalhorn case studied at Ku band. It should be noted that the optimal feedaperture size may differ based on the main reflector diameter and thesatellite communication band being used, be it any of L, S, C, X, Ku, K,or Ka bands. For example, the optimal feed aperture size may be largerfor C-band communication and may be smaller for Ka-band communication.FIG. 69B illustrates pictorially the three cases described at the bottomof FIG. 69A. As shown in Case A, feed horns with 80 mm diameters providebeams with 415 km diameters, defined as half-power beam width (“HPBW”).However, the centers of the beams are separated by 600 km, which leavesabout 185 km of space between the beams where insufficient coverage isprovided. In Case B, the diameters of the horn antennas are decreased to40 mm, which causes the beams to overlap. However, the use of thesmaller diameter feed horn results in a 2 dB loss in directivity. Inideal Case C, 80 mm diameter feed horns are used where they physicallyintersect to produce overlapping beams. However, this configuration isnot physically possible.

FIGS. 70A-B show that the optimal horn size may be used if the horn iscreated by combining seven conically shaped horns having circular crosssections. It will be appreciated that numbers either larger or smallerthan 7 feed horns can also be used to approximate a single larger feedhorn. As shown in FIG. 70A, the seven antennas are grouped together tohave a diameter of 80 mm to replicate the directivity of a single feedhorn antenna having a diameter of 80 mm. Each cylinder may have adiameter of 26 mm. The graphs of FIG. 70B show that between +/−18degrees, the directivity of the seven horns is almost identical to thedirectivity of the single feed horn with a 80 mm diameter, where 18degrees is the angle from boresight of feed horn to edge of reflector inthe example case, and therefore any differences between single optimal80 mm feed horn and aggregate feed pattern of the 7 feed horns beyond 18degrees does not cause a difference in overall system performance. Itshould be appreciated that the diameter of the seven feed horns maychange based on requirements, frequencies, and/or implementations. Forexample, smaller feed horns may approximate a larger feed horn with adiameter between 10 mm to 250 mm.

FIGS. 71A-71B show diagrams that compare a scanning performance of a 3meter reflector with two large feed horn antennas with 80 mm diameters(i.e., Feed 1 and Feed 2) and groups of seven cylindrical fed hornantennas (i.e., Feed groups 1 to 4). As shown, there is close to a1-degree shift when switching between the larger 80 mm diameter antennaswhen they are placed immediately next to each other with their edgestouching. In contrast, since any seven of the small feed horns may beselected, so long as a 2-3-2 arrangement is activated to approximate thelarger 80 mm antenna, small theta shifts can be realized, enablingscanning with 0.33 degree shifts between selection of different feedgroups since there is a 26 mm separation of beam centers compared to an80 mm separation for the larger feed horn antennas.

In one example of exploiting this improved resolution, the SDR activatesfirst, second, and third feed groups in sequence and over time, whereineach feed group comprises seven feed horns arranged in 2-3-2 order, andeach activated feed group is displaced from a previously activated feedgroup by the width of one feed horn. Such a scenario can be used, forexample, to continuously illuminate a spot beam tracking the progress ofa cruise ship, or an airplane.

FIG. 72 shows a diagram of an array 7200 of 61 feed horn antennas. Inthe first image, a single beam is created by activating seven of the 61feed horn antennas. In the second image, seven beams are created byactivating 25 of the feed horn antennas. As shown, some of the feed hornantennas form more than one beam. In other words, different feed groupscan include the same feed horn antenna to produce respective beams. Athird image shows the 37 possible beams that may be created from the 61different feed horn antennas.

Several observations about disclosed embodiments can be gleaned fromFIGS. 67-72, and elsewhere. Each of the antennas in the antenna systemof the disclosed communication satellite includes one or more feedhorns, and the terrestrial coverage area is provided by a spot beamprovided by each group of one or more active feed horns. The terrestrialcoverage area of each of the spot beams increases as more power isprovided to the antenna and decreases as less power is provided to theantenna. In some embodiments, the SDR is configured to maximizedirectivity of the spot beam and the terrestrial coverage area byexciting each of the feed horns with maximum, equal amplitude inputs. Insome embodiments, the SDR is configured to produce a narrower spot beamby increasing an offset distance between its feed horns. In some otherembodiments, the SDR is configured to successively alter a phase of eachfeed horn input, thereby steering the spot beam to a desired direction.

FIG. 73 shows a diagram of possible hardware configurations forselecting the different feed horn groups, according to exampleembodiments of the present disclosure. In a digital configuration 7302,the SDR 206 described above is configured to use digital internalrouting to select 24 of 37 possible converters for selection of the feedhorn groups. The SDR 206 is communicatively coupled to 37 Ku-bandconverters and a beam forming network. For the digital configuration7302, RF switches and associated control components are not needed. Insome examples, the SDR 206 may provide for full flexibility so that anyinput can be provided to any of the 37 beams.

It should be appreciated that a power amplifier is provided for eachfeed horn antenna. In some embodiments, the power amplifier is asolid-state power amplifier (“SSPA”). In other embodiments, the poweramplifier is a traveling-wave tube amplifier (“TWTA”), or a Klystronpower amplifier (“KPA”). A failure of an amplifier will not take down anentire beam since other antennas would still be operational. A singleamplifier failure would only reduce performance of the beam. An entirebeam could only be taken down with the failure of seven adjacentantennas or amplifiers, which is not likely. As such, the use of thefeed array provides for graceful degradation in performance in the eventof one or more failures, thereby increasing the robustness of thesatellite system disclosed herein.

In contrast an analog configuration provides a switching networkconnected to the SDR 206 via 24 Ku-band converters. The switchingnetwork maps the 24 inputs from the converters (corresponding to themaximum number of beams that may be activated due to powerconsiderations) to the 37 possible beams of the antenna array. In thisconfiguration, less overhead is needed for the SDR 206 for internalrouting.

FIG. 74 shows a diagram of possible RF switches. As illustrated, an SPDTswitch can route an input from one of two outputs, while an SP3T canroute an input to one of three outputs, a SP4T routes an input to one offour outputs, and SP8T routes an input to one of eight outputs. Theexample switching network of FIG. 73 may include any number ofcombinations of RF switches to enable selection of the 37 beams fortransmission or reception of data. The use of high-order switchesprovides additional flexibility in beam illumination at the expense ofan increased circuit area.

FIG. 75 shows a diagram of a switching network of FIG. 73 using SP4Tswitches, according to an example embodiment of the present disclosure.While the switching network shows a single layer of SP4T switches, inanother example, the switching network may include additional layersand/or different types of switches, such as those shown in FIG. 73. Asillustrated in FIG. 75, each of the four outputs from each switch isconnected to four over the 37 switching network outputs. As such, eachof the 37 outputs are connected to many outputs of the SP4T switches.Such a configuration provides enough degrees of freedom to illuminatethe vast majority of the possible combinations of beams, therebyproviding system flexibility.

FIG. 76 shows a diagram of an example use-case of the switching network,according to an example embodiment of the present disclosure. In theexample, three of 24 inputs are shown, where the switching network iscapable of routing each input to one of four possible outputs, shown inbeam area 7600. Thus, the blue (diagonal-hatched) input may be providedto any one of the four blue (diagonal-hatched) circles shown in beamarea 7600 while the red (cross-hatched) input may be provided to any oneof the red (cross-hatched) circles. It should be noted that theswitching network provides for an input to be provided at differentparts of the array area 7600 rather than concentrating a single beam toone location of the area. Example possible beam configurations are shownto the left in FIG. 76. It should be noted that the beam forming networkprovides for the selection of the seven individual feed horn antennasthat are configured to form the respective beam.

FIG. 77 shows a diagram of different satellite configurations using theantenna configuration described above. In this example the satellitesare in the same orbital slot. The figure shows activated spot beams assolid circles, where satellite A is shown as cross-hatched circles withsolid borders, and satellite B is shown as diagonal-hatched circles withdashed borders. In a first configuration 7702, the satellites provideoverlapping coverage to illuminate 37 beams. However, this configurationprovides for 11 un-utilized transponders. In a second configuration7704, the coverage is partially overlapped between the two satellites.Here, 48 of the 51 beams are illuminated in the coverage area and thesatellite transponders are fully utilized. In a third configuration7706, the coverage area is non-overlapping. As such, only 48 of the 74beams are illuminated but the transponders are fully utilized.

Further Examples

The following examples describe various examples of configurations andembodiments of the disclosed invention, as described above.

Example 1 provides an exemplary Geostationary (GEO) communicationsatellite including: an antenna system including a plurality ofantennas, each of the antennas configured to provide a communicationcoverage region having an adjustable bandwidth for a terrestrialcoverage area while the antenna is in an active state and the satelliteis in an orbit above Earth, a front-end subsystem communicativelycoupled to the antenna system, the front-end subsystem including aninput side including an input filter and an analog-to-digital converter,and an output side including an output filter and a digital-to-analogconverter and a software defined radio (“SDR”) communicatively coupledto the antenna system via the front-end subsystem, and wherein the SDR,in response to a surge modification request, modifies a bandwidth ofeach active antenna by increasing or decreasing a share of a satellitepower budget allotted to the antenna. The share of satellite powerbudget allotted to the antenna can be increased by deactivating another,previously active antenna. Or, the share can be decreased by activatinganother, previously inactive antenna. In some embodiments, thecommunication coverage area is a spot beam.

Example 2 includes the substance of the exemplary GEO communicationsatellite of Example 1, wherein the surge modification request includesa predetermined routine, instructions received from a ground station, oran indication of a coverage area, and the SDR is configured to implementa super-surge by dynamically increasing forward throughput to a targetregion requiring higher bandwidth.

Example 3 includes the substance of the exemplary GEO communicationsatellite of Example 2, wherein the ground station includes a teleportthat communicates with the satellite according to codified InternationalTelecommunication Union Radiocommunication Sector (ITU-R) standards.

Example 3.1 includes the substance of the exemplary GEO communicationsatellite of Example 2, wherein the SDR is further configured toimplement the super surge by either dynamically increasing forwardthroughput of a first antenna and dynamically increasing returnthroughput of a second antenna, or dynamincally increasing both forwardand return throughput of the first antenna simultaneously.

Example 4 includes the substance of the exemplary GEO communicationsatellite of Example 2, wherein the SDR is further configured toincrease power provided to a first antenna illuminating the targetregion by deactivating a second, previously active antenna immediatelyadjacent to the first antenna, wherein the first antenna becomes a solerecipient of a solid state power amplifier that previously also providedan input to the second antenna.

Example 5 includes the substance of the exemplary GEO communicationsatellite of Example 1, wherein the terrestrial coverage area isprovided by the spot beam provided by each active antenna wherein theterrestrial coverage area of each of the spot beams increases as morepower is provided to the antenna, and decreases as less power isprovided to the antenna.

Example 6 includes the substance of the exemplary GEO communicationsatellite of Example 1, wherein each of the plurality of antennasincludes a plurality of feed horns configured to produce the spot beamoff of a reflector, wherein the antenna is configured to maximizedirectivity of the spot beam and the terrestrial coverage area byexciting each of the feed horns with maximum, equal amplitude inputs.

Example 7 includes the substance of the exemplary GEO communicationsatellite of Example 1, wherein each of the plurality of antennasincludes a plurality of feed horns configured to produce the spot beamoff of a reflector, wherein a first antenna is configured to produce anarrower spot beam by increasing an offset distance between its feedhorns.

Example 8 includes the substance of the exemplary GEO communicationsatellite of Example 1, wherein each of the plurality of antennasincludes a plurality of feed horns configured to produce the spot beamoff of a reflector, and wherein a first antenna is configured to alter aphase of each feed horn input, thereby steering the spot beam to adesired direction.

Example 9 includes the substance of the exemplary GEO communicationsatellite of Example 1, wherein each of the plurality of antennasincludes one or more feed horns.

Example 10.1 includes the substance of the exemplary GEO communicationsatellite of Example 1, wherein the SDR further activates first, second,and third feed groups in sequence and over time, wherein each feed groupincludes seven feed horns arranged in 2-3-2 order, and each activatedfeed group is displaced from a previously activated feed group by oneantenna width.

Example 10.2 includes the substance of the exemplary GEO communicationsatellite of Example 1, wherein the SDR further activates first, second,and third feed groups in sequence and over time, wherein each feed groupcomprises three, four, five, six, seven, eight, or nine feed hornsarranged in polygonal order, and each activated feed group is displacedfrom a previously activated feed group by a width of one feed horn.

Example 11 provides an exemplary method including: providing aGeostationary (GEO) communication satellite comprising an antenna systemincluding a plurality of antennas, each of the antennas configured toprovide a communication radiation pattern having an adjustable bandwidthfor a terrestrial coverage area while the antenna is in an active stateand the satellite is in an orbit above Earth, a front-end subsystemcommunicatively coupled to the antenna system, the front-end subsystemincluding an input side including an input filter and ananalog-to-digital converter, and an output side including an outputfilter and a digital-to-analog converter, and a software defined radio(“SDR”) communicatively coupled to the antenna system via the front-endsubsystem, and responding, by the SDR in response to a surgemodification request, by modifying a bandwidth of each active antenna byincreasing or decreasing a share of a satellite power budget allotted tothe antenna by deactivating or activating a previously active orpreviously inactive antenna, respectively. In some embodiments, thecommunication radiation pattern is a spot beam.

Example 12 includes the substance of the exemplary method of Example 11,wherein the surge modification request includes a predetermined routine,instructions received from a ground station, or an indication of acoverage area, and the SDR is configured to implement a super-surge bydynamically increasing forward throughput to a target region requiringhigher bandwidth.

Example 13 includes the substance of the exemplary method of Example 12,wherein the ground station includes a teleport that communicates withthe satellite according to codified International TelecommunicationUnion Radiocommunication Sector (ITU-R) standards.

Example 14 includes the substance of the exemplary method of Example 12,further including the SDR increasing power provided to a first antennailluminating the target region by deactivating a second, previouslyactive antenna immediately adjacent to the first antenna, wherein thefirst antenna becomes a sole recipient of a solid state power amplifierthat previously also provided an input to the second antenna.

Example 15 includes the substance of the exemplary method of Example 11,wherein the terrestrial coverage area is provided by the spot beamprovided by each active antenna wherein the terrestrial coverage area ofeach of the spot beams increases as more power is provided to theantenna, and decreases as less power is provided to the antenna.

Example 16 includes the substance of the exemplary method of Example 11,wherein each of the plurality of antennas includes a plurality of feedhorns configured to produce the spot beam off of a reflector, whereinthe antenna is configured to maximize directivity of the spot beam andthe terrestrial coverage area by exciting each of the feed horns withmaximum, equal amplitude inputs.

Example 17 includes the substance of the exemplary method of Example 11,wherein each of the plurality of antennas includes a plurality of feedhorns configured to produce the spot beam off of a reflector, wherein afirst antenna is configured to produce a narrower spot beam byincreasing an offset distance between its feed horns.

Example 18 includes the substance of the exemplary method of Example 11,wherein each of the plurality of antennas includes a plurality of feedhorns configured to produce the spot beam off of a reflector, andwherein a first antenna is configured to alter a phase of each feed horninput, thereby steering the spot beam to a desired direction.

Example 19 includes the substance of the exemplary method of Example 11,wherein each of the plurality of antennas includes one or more feedhorns.

Example 20 includes the substance of the exemplary method of Example 11,further including the SDR activating first, second, and third feedgroups in sequence and over time, wherein each feed group includes sevenfeed horns arranged in 2-3-2 order, and each activated feed group isdisplaced from a previously activated feed group by one antenna width.

CONCLUSION

It will be appreciated that each of the systems, structures, methods,and procedures described herein may be implemented using one or morecomputer program or component. These programs and components may beprovided as a series of computer instructions on any conventionalcomputer-readable medium, including read only memory (“ROM”), flashmemory, magnetic or optical disks, optical memory, or other storagemedia, and combinations and derivatives thereof. The instructions may beconfigured to be executed by a processor, which when executing theseries of computer instructions performs or facilitates the performanceof all or part of the disclosed methods and procedures.

It should be understood that various changes and modifications to theexample embodiments described herein will be apparent to those skilledin the art. Such changes and modifications can be made without departingfrom the spirit and scope of the present subject matter and withoutdiminishing its intended advantages. It is therefore intended that suchchanges and modifications be covered by the appended claims. Moreover,consistent with current U.S. law, it should be appreciated that 35U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, paragraph 6 is not intended tobe invoked unless the terms “means”, or “step” are explicitly recited inthe claims. Accordingly, the claims are not meant to be limited to thecorresponding structure, material, or actions described in thespecification or equivalents thereof

What is claimed is:
 1. A Geostationary (GEO) communication satellitecomprising: an antenna system comprising a plurality of antennas, eachof the antennas configured to provide a communication coverage regionhaving an adjustable bandwidth for a terrestrial coverage area while theantenna is in an active state and the satellite is in an orbit aboveEarth; a front-end subsystem communicatively coupled to the antennasystem, the front-end subsystem comprising an input side including aninput filter and an analog-to-digital converter, and an output sideincluding an output filter and a digital-to-analog converter; and asoftware defined radio (“SDR”), communicatively coupled to the antennasystem via one or more user slices combined or split with the input sideor the output side of the front-end subsystem, wherein each of one ormore user slices are configured to communicate with one or more distinctgateway slices, wherein the SDR is configured to selectively increase ordecrease the throughput of each of the active antennas.
 2. The GEOcommunication satellite of claim 1, wherein the one or more user slicesare configured to provide beams for user terminals, and the one or moredistinct gateway slice are configured to communication with a gatewaystation.
 3. The GEO communication satellite of claim 1, wherein the SDRdetermines whether a surge modification request has been received, andif a surge modification request has not been received, waiting for apredetermined amount of time before determining whether another surgemodification request has been received.
 4. The GEO communicationsatellite of claim 1, wherein the SDR, provides a first throughput ofone more of the active antennas for a first terrestrial area and asecond throughput for of the one or more the active antennas for asecond terrestrial area, wherein the first throughput is greater thanthe second throughput.
 5. The GEO communication satellite of claim 1,wherein the SDR, in response to a surge modification request, modifies athroughput of each active antenna by increasing or decreasing a share ofa satellite power budget allotted to the antenna by deactivating oractivating a previously active or previously inactive antenna,respectively.
 6. The GEO communication satellite of claim 5, wherein thesurge modification request comprises a predetermined routine,instructions received from a ground station, or an indication of acoverage area, and the SDR is configured to implement a super-surge bydynamically increasing one or both of forward and return throughput to atarget region requiring higher bandwidth.
 7. The GEO communicationsatellite of claim 5, wherein the terrestrial coverage area is providedby the communication coverage region provided by each active antennawherein the terrestrial coverage area of each of the communicationcoverage regions increases as more power is provided to the antenna, anddecreases as less power is provided to the antenna.
 8. The GEOcommunication satellite of claim 5, wherein each of the plurality ofantennas comprises a plurality of feed horns configured to produce thecommunication coverage region off of a reflector, wherein the antenna isconfigured to maximize directivity of the communication coverage regionby exciting each of the feed horns with maximum, equal amplitude inputs.9. The GEO communication satellite of claim 5, wherein each of theplurality of antennas comprises a plurality of feed horns configured toproduce the communication coverage region off of a reflector, wherein afirst antenna is configured to produce a narrower spot beam byincreasing an offset distance between its feed horns.
 10. The GEOcommunication satellite of claim 5, wherein each of the plurality ofantennas comprises a plurality of radiating antenna elements configuredto produce the communication coverage region off of a reflector, andwherein a first antenna is configured to alter a phase of each radiatingantenna element input, thereby steering the communication coverageregion to a desired direction.
 11. A method comprising: providing aGeostationary (GEO) communication satellite comprising: an antennasystem comprising a plurality of antennas, each of the antennasconfigured to provide a communication coverage region having anadjustable bandwidth for a terrestrial coverage area while the antennais in an active state and the satellite is in an orbit above Earth; afront-end subsystem communicatively coupled to the antenna system, thefront-end subsystem comprising an input side including an input filterand an analog-to-digital converter, and an output side including anoutput filter and a digital-to-analog converter; and a software definedradio (“SDR”), communicatively coupled to the antenna system via one ormore user slices combined or split with the input side or the outputside of the front-end subsystem, wherein each of one or more user slicesare configured to communicate with one or more distinct gateway slices,wherein the SDR is configured to selectively increase or decrease thethroughput of each of the active antennas.
 12. The method of claim 11,further comprising: providing by one or more user slices beams for userterminals, and communicating by one or more distinct gateway slice witha gateway station.
 13. The method of claim 11, further comprising:determining whether a surge modification request has been received, andif a surge modification request has not been received, waiting for apredetermined amount of time before determining whether another surgemodification request has been received.
 14. The method of claim 11,further comprising: providing a first throughput of one more of theactive antennas for a first terrestrial area and a second throughput forof the one or more the active antennas for a second terrestrial area,wherein the first throughput is greater than the second throughput. 15.The method of 11, further comprising: in response to a surgemodification request, modifying a throughput of each active antenna byincreasing or decreasing a share of a satellite power budget allotted tothe antenna by deactivating or activating a previously active orpreviously inactive antenna, respectively.
 16. The method of claim 15,wherein the surge modification request comprises a predeterminedroutine, instructions received from a ground station, or an indicationof a coverage area, and the SDR is configured to implement a super-surgeby dynamically increasing one or both of forward and return throughputto a target region requiring higher bandwidth.
 17. The method of claim15, wherein the terrestrial coverage area is provided by thecommunication coverage region provided by each active antenna whereinthe terrestrial coverage area of each of the communication coverageregions increases as more power is provided to the antenna, anddecreases as less power is provided to the antenna.
 18. The method ofclaim 15, wherein each of the plurality of antennas comprises aplurality of feed horns configured to produce the communication coverageregion off of a reflector, wherein the antenna is configured to maximizedirectivity of the communication coverage region by exciting each of thefeed horns with maximum, equal amplitude inputs.
 19. The method of claim15, wherein each of the plurality of antennas comprises a plurality offeed horns configured to produce the communication coverage region offof a reflector, wherein a first antenna is configured to produce anarrower spot beam by increasing an offset distance between its feedhorns.
 20. The method of claim 15, wherein each of the plurality ofantennas comprises a plurality of radiating antenna elements configuredto produce the communication coverage region off of a reflector, andwherein a first antenna is configured to alter a phase of each radiatingantenna element input, thereby steering the communication coverageregion to a desired direction.